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2025 · trial · Physical Sciences — Physics · Grade 12

Grade 12 Physical Sciences P1 — KZN trial

Notes

Answer all questions. Show working. Calculators allowed unless stated. g = 9.8 m·s⁻².

90 min · 146 Marks · 30 questions

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Question breakdown

  1. 1.1 · 10 Marks

    p of 0.5 kg at 8 m·s⁻¹

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: p of 0.5 kg at 8 m·s⁻¹

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 0.5 kg · 8 m·s⁻¹. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: 5 kg at 8 m·s⁻¹. Circle that word — that is the missing variable.

    Find

    We are required to find: 5 kg at 8 m·s⁻¹. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: p=mv=4. Then substitute the given, one line at a time, to get 5 kg at 8 m·s⁻¹.

    In other words — as if you have never seen this before

    If you have never seen this before: p=mv=4. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 0.5 kg · 8 m·s⁻¹. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    p=mv=4.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 0.5 kg · 8 m·s⁻¹. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: 5 kg at 8 m·s⁻¹. Circle that word — that is the missing variable. Find: We are required to find: 5 kg at 8 m·s⁻¹. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: p=mv=4. Then substitute the given, one line at a time, to get 5 kg at 8 m·s⁻¹.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 0.5 kg · 8 m·s⁻¹. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      p=mv=4.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      p=mv=4.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      4 kg·m·s⁻¹

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    4 kg·m·s⁻¹

    Copy onto your answer sheet — in this order

    Answer: 4 kg·m·s⁻¹

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  2. 1.2 · 12 Marks · Work, energy & power

    Work at 90° to displacement is

    Formulas

    W=F Δx cosθ

    Work

    P=WΔt=F v

    Power

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Work at 90° to displacement is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 90°. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Work at 90° to displacement is. Circle that word — that is the missing variable.

    Find

    We are required to find: Work at 90° to displacement is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: cos 90° = 0. Then substitute the given, one line at a time, to get Work at 90° to displacement is.

    In other words — as if you have never seen this before

    If you have never seen this before: cos 90° = 0. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 90°. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    cos 90°=0.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 90°. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Work at 90° to displacement is. Circle that word — that is the missing variable. Find: We are required to find: Work at 90° to displacement is. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: cos 90° = 0. Then substitute the given, one line at a time, to get Work at 90° to displacement is.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 90°. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      cos 90°=0.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      cos 90°=0.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      0 J

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    0 J

    Copy onto your answer sheet — in this order

    Answer: 0 J

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  3. 2.1 · 14 Marks

    hf = W₀ + E_k. If f increases, E_k

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: hf = W₀ + E_k. If f increases, E_k

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: If f increases, E_k. Circle that word — that is the missing variable.

    Find

    We are required to find: If f increases, E_k. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: Linear graph of E_k vs f. Then substitute the given, one line at a time, to get If f increases, E_k.

    In other words — as if you have never seen this before

    If you have never seen this before: Linear graph of E_k vs f. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    Linear graph of E_k vs f.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: If f increases, E_k. Circle that word — that is the missing variable. Find: We are required to find: If f increases, E_k. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: Linear graph of E_k vs f. Then substitute the given, one line at a time, to get If f increases, E_k.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      Linear graph of E_k vs f.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      Linear graph of E_k vs f.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      increases

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    increases

    Copy onto your answer sheet — in this order

    Answer: increases

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  4. 2.2 · 14 Marks

    Vrms=230 V. Vmax ≈

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: V_rms = 230 V. V_max ≈

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 230 V. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: V_max ≈. Circle that word — that is the missing variable.

    Find

    We are required to find: V_max ≈. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: ×√2. Then substitute the given, one line at a time, to get V_max ≈.

    In other words — as if you have never seen this before

    If you have never seen this before: ×√2. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 230 V. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    ×√2.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 230 V. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: V_max ≈. Circle that word — that is the missing variable. Find: We are required to find: V_max ≈. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: ×√2. Then substitute the given, one line at a time, to get V_max ≈.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 230 V. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      ×√2.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      ×√2.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      325 V

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    325 V

    Copy onto your answer sheet — in this order

    Answer: 325 V

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  5. 3.1 · 15 Marks

    Two equal masses stick after a 1D collision. v_f is

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Two equal masses stick after a 1D collision. v_f is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 1D. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: v_f is. Circle that word — that is the missing variable.

    Find

    We are required to find: v_f is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: m v = 2m v_f. Then substitute the given, one line at a time, to get v_f is.

    In other words — as if you have never seen this before

    If you have never seen this before: m v = 2m v_f. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 1D. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    m v=2m vf.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 1D. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: v_f is. Circle that word — that is the missing variable. Find: We are required to find: v_f is. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: m v = 2m v_f. Then substitute the given, one line at a time, to get v_f is.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 1D. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      m v=2m vf.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      m v=2m vf.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      half the incoming v if target at rest

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    half the incoming v if target at rest

    Copy onto your answer sheet — in this order

    Answer: half the incoming v if target at rest

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  6. 3.2 · 15 Marks

    Source moving away. Observed f is

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Source moving away. Observed f is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Observed f is. Circle that word — that is the missing variable.

    Find

    We are required to find: Observed f is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: Plus in the denominator. Then substitute the given, one line at a time, to get Observed f is.

    In other words — as if you have never seen this before

    If you have never seen this before: Plus in the denominator. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    Plus in the denominator.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Observed f is. Circle that word — that is the missing variable. Find: We are required to find: Observed f is. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: Plus in the denominator. Then substitute the given, one line at a time, to get Observed f is.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      Plus in the denominator.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      Plus in the denominator.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      lower

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    lower

    Copy onto your answer sheet — in this order

    Answer: lower

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  7. 7 · 2 Marks · Momentum & impulse

    Momentum of 2 kg at 3 m·s⁻¹ is

    NWFf

    Formulas

    p=m v

    Momentum

    Fnet Δt=Δp

    Impulse-momentum theorem

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Momentum of 2 kg at 3 m·s⁻¹ is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 2 kg · 3 m·s⁻¹. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Momentum of 2 kg at 3 m·s⁻¹ is. Circle that word — that is the missing variable.

    Find

    We are required to find: Momentum of 2 kg at 3 m·s⁻¹ is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: p = mv = 6 kg·m·s⁻¹. Then substitute the given, one line at a time, to get Momentum of 2 kg at 3 m·s⁻¹ is.

    In other words — as if you have never seen this before

    p=mv=6 kg·m·s⁻¹.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 2 kg · 3 m·s⁻¹. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    p=mv=6 kg·m·s⁻¹.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 2 kg · 3 m·s⁻¹. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Momentum of 2 kg at 3 m·s⁻¹ is. Circle that word — that is the missing variable. Find: We are required to find: Momentum of 2 kg at 3 m·s⁻¹ is. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: p = mv = 6 kg·m·s⁻¹. Then substitute the given, one line at a time, to get Momentum of 2 kg at 3 m·s⁻¹ is.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 2 kg · 3 m·s⁻¹. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      p=mv=6 kg·m·s⁻¹.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      p=mv=6 kg·m·s⁻¹.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      6 kg·m·s⁻¹

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    6 kg·m·s⁻¹

    Copy onto your answer sheet — in this order

    Answer: 6 kg·m·s⁻¹

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  8. 8 · 2 Marks

    Thrown up at 14.7 m·s⁻¹. Time to top? (g=9.8)

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Thrown up at 14.7 m·s⁻¹. Time to top? (g=9.8)

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 14.7 m·s⁻¹ · 9.8. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: 8). Circle that word — that is the missing variable.

    Find

    We are required to find: 8). Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: v_f=0=v_i+a t. Then substitute the given, one line at a time, to get 8).

    In other words — as if you have never seen this before

    vf=0=vi+a t→t=14.79.8=1.5 s.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 14.7 m·s⁻¹ · 9.8. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    vf=0=vi+a t→t=14.79.8=1.5 s.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 14.7 m·s⁻¹ · 9.8. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: 8). Circle that word — that is the missing variable. Find: We are required to find: 8). Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: v_f=0=v_i+a t. Then substitute the given, one line at a time, to get 8).

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 14.7 m·s⁻¹ · 9.8. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      vf=0=vi+a t→t=14.79.8=1.5 s.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      vf=0=vi+a t→t=14.79.8=1.5 s.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      1.5 s

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    1.5 s

    Copy onto your answer sheet — in this order

    Answer: 1.5 s

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  9. 9 · 4 Marks · Work, energy & power

    Work by 80 N through 5 m at 60°

    Formulas

    W=F Δx cosθ

    Work

    P=WΔt=F v

    Power

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Work by 80 N through 5 m at 60°

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 80 N · 5 m · 60°. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Work by 80 N through 5 m at 60°. Circle that word — that is the missing variable.

    Find

    We are required to find: Work by 80 N through 5 m at 60°. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: 200 J. Then substitute the given, one line at a time, to get Work by 80 N through 5 m at 60°.

    In other words — as if you have never seen this before

    200 J

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 80 N · 5 m · 60°. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    200 J

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 80 N · 5 m · 60°. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Work by 80 N through 5 m at 60°. Circle that word — that is the missing variable. Find: We are required to find: Work by 80 N through 5 m at 60°. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: 200 J. Then substitute the given, one line at a time, to get Work by 80 N through 5 m at 60°.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 80 N · 5 m · 60°. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      200 J

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      W = F Δx cosθ = 80 × 5 × cos 60° = 400 × 0.5 = 200 J. The cosine picks only the component along the displacement.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      200 J

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    200 J

    Copy onto your answer sheet — in this order

    Answer: 200 J

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  10. 10 · 2 Marks

    Two equal masses stick (1D, target at rest). v_f is

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Two equal masses stick (1D, target at rest). v_f is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 1D. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: v_f is. Circle that word — that is the missing variable.

    Find

    We are required to find: v_f is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: half the incoming v. Then substitute the given, one line at a time, to get v_f is.

    In other words — as if you have never seen this before

    half the incoming v

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 1D. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    half the incoming v

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 1D. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: v_f is. Circle that word — that is the missing variable. Find: We are required to find: v_f is. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: half the incoming v. Then substitute the given, one line at a time, to get v_f is.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 1D. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      half the incoming v

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      m v = 2m v_f → v_f = v2. Momentum conserved, kinetic energy is not.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      half the incoming v

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    half the incoming v

    Copy onto your answer sheet — in this order

    Answer: half the incoming v

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  11. 11 · 2 Marks · Work, energy & power

    Increasing intensity (f > f₀) increases

    Formulas

    W=F Δx cosθ

    Work

    P=WΔt=F v

    Power

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Increasing intensity (f > f₀) increases

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Increasing intensity (f > f₀) increases. Circle that word — that is the missing variable.

    Find

    We are required to find: Increasing intensity (f > f₀) increases. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: More photons, not more energy each. Then substitute the given, one line at a time, to get Increasing intensity (f > f₀) increases.

    In other words — as if you have never seen this before

    More photons, not more energy each.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    More photons, not more energy each.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Increasing intensity (f > f₀) increases. Circle that word — that is the missing variable. Find: We are required to find: Increasing intensity (f > f₀) increases. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: More photons, not more energy each. Then substitute the given, one line at a time, to get Increasing intensity (f > f₀) increases.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      More photons, not more energy each.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      More photons, not more energy each.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      number of photoelectrons per second

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    number of photoelectrons per second

    Copy onto your answer sheet — in this order

    Answer: number of photoelectrons per second

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  12. 12 · 3 Marks

    Source approaching. Observed f is

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Source approaching. Observed f is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Observed f is. Circle that word — that is the missing variable.

    Find

    We are required to find: Observed f is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: greater than source f. Then substitute the given, one line at a time, to get Observed f is.

    In other words — as if you have never seen this before

    greater than source f

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    greater than source f

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Observed f is. Circle that word — that is the missing variable. Find: We are required to find: Observed f is. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: greater than source f. Then substitute the given, one line at a time, to get Observed f is.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      greater than source f

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      Doppler blueshift of sound: higher pitch.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      greater than source f

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    greater than source f

    Copy onto your answer sheet — in this order

    Answer: greater than source f

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  13. 13 · 3 Marks

    SA mains RMS is

    Notes: South African household alternating voltage. The paper wants RMS, not peak.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: SA mains RMS is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: SA mains RMS is. Circle that word — that is the missing variable.

    Find

    We are required to find: SA mains RMS is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write V_rms = 230 V with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives SA mains RMS is.

    In other words — as if you have never seen this before

    NSC uses 230 V RMS. Vmax=Vrms √2 ≈ 325 V.

    2. What do we already know?

    South African household alternating voltage. The paper wants RMS, not peak.

    3. Which method — and why this one?

    NSC uses 230 V RMS. Vmax=Vrms √2 ≈ 325 V.

    4. Step-by-step working

    1. 01 / 05

      Quote the standard

      V_rms = 230 V in South Africa.

      Vrms=230 V

      Why this step: Write the formula before numbers. The memo awards a method mark for the law even if a digit slips later.

    2. 02 / 05

      Peak is different

      V_max = 230√2 ≈ 325 V. That is the option you must not pick when they ask RMS.

      Vmax ≈ 325 V

      Why this step: One job per line so you can find a slip, and so a marker can follow the marks.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      230 V

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    230 V

    Copy onto your answer sheet — in this order

    Formula: Vrms=230 V

    Answer: 230 V

    6. Check it like a marker

    Older textbooks said 220 V. Current CAPS/NSC: 230 V.

    7. A trap first-timers fall into

    325 V is the peak, not RMS. 110 V is North American.

  14. 14 · 3 Marks

    230 V RMS. V_max ≈

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: 230 V RMS. V_max ≈

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 230 V. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: V_max ≈. Circle that word — that is the missing variable.

    Find

    We are required to find: V_max ≈. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: 325 V. Then substitute the given, one line at a time, to get V_max ≈.

    In other words — as if you have never seen this before

    325 V

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 230 V. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    325 V

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 230 V. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: V_max ≈. Circle that word — that is the missing variable. Find: We are required to find: V_max ≈. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: 325 V. Then substitute the given, one line at a time, to get V_max ≈.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 230 V. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      325 V

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Reason

      Vmax=Vrms √2 ≈ 325 V.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      325 V

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    325 V

    Copy onto your answer sheet — in this order

    Answer: 325 V

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  15. 15 · 3 Marks · Work, energy & power

    Work by 50 N through 4 m at 60°

    Formulas

    W=F Δx cosθ

    Work

    P=WΔt=F v

    Power

    Notes: F=50 N, Δx=4 m, θ=60°, cos60°=0.5.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Work by 50 N through 4 m at 60°

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 50 N · 4 m · 60°. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Work by 50 N through 4 m at 60°. Circle that word — that is the missing variable.

    Find

    We are required to find: Work by 50 N through 4 m at 60°. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write W = FΔx cosθ with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives Work by 50 N through 4 m at 60°.

    In other words — as if you have never seen this before

    W=FΔx cosθ=50×4×0.5=100 J.

    2. What do we already know?

    F=50 N, Δx=4 m, θ=60°, cos60°=0.5.

    3. Which method — and why this one?

    W=FΔx cosθ=50×4×0.5=100 J.

    4. Step-by-step working

    1. 01 / 05

      Write W = FΔx cosθ

      Use cosine, not sine.

      W=FΔx cosθ

      Why this step: Write the formula before numbers. The memo awards a method mark for the law even if a digit slips later.

    2. 02 / 05

      Substitute

      50×4×0.5=100 J.

      W=100 J

      Why this step: One job per line so you can find a slip, and so a marker can follow the marks.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      100 J

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    100 J

    Copy onto your answer sheet — in this order

    Formula: W=FΔx cosθ

    Answer: 100 J

    6. Check it like a marker

    200 J would be if cos were 1. At 60° you only get half.

    7. A trap first-timers fall into

    Do not use sin60° ≈ 0.866, which would give ~173 J, not an option here but a common slip.

  16. 16 · 3 Marks · Work, energy & power

    Force 8 N through 3 m at 60°. Work?

    Formulas

    W=F Δx cosθ

    Work

    P=WΔt=F v

    Power

    Notes: F=8 N, Δx=3 m, θ=60°, cos60°=0.5.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Force 8 N through 3 m at 60°. Work?

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 8 N · 3 m · 60°. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Work. Circle that word — that is the missing variable.

    Find

    We are required to find: Work. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write W = FΔx cosθ with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives Work.

    In other words — as if you have never seen this before

    W=F Δx cosθ.

    2. What do we already know?

    F=8 N, Δx=3 m, θ=60°, cos60°=0.5.

    3. Which method — and why this one?

    W=F Δx cosθ.

    4. Step-by-step working

    1. 01 / 05

      Write the formula

      Only the component along the displacement does work.

      W=FΔx cosθ

      Why this step: Write the formula before numbers. The memo awards a method mark for the law even if a digit slips later.

    2. 02 / 05

      Substitute

      W=8×3×0.5=12 J.

      W=12 J

      Why this step: One job per line so you can find a slip, and so a marker can follow the marks.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      12 J

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    12 J

    Copy onto your answer sheet — in this order

    Formula: W=FΔx cosθ

    Answer: 12 J

    6. Check it like a marker

    cos60° is 12, not √32. 24 J would be if you forgot the cosine.

    7. A trap first-timers fall into

    Do not use sin60°. Work uses the adjacent component, cosine.

  17. 17 · 2 Marks

    Opposite charges

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Opposite charges

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Opposite charges. Circle that word — that is the missing variable.

    Find

    We are required to find: Opposite charges. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: Unlike attract. Then substitute the given, one line at a time, to get Opposite charges.

    In other words — as if you have never seen this before

    Unlike attract.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    Unlike attract.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Opposite charges. Circle that word — that is the missing variable. Find: We are required to find: Opposite charges. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: Unlike attract. Then substitute the given, one line at a time, to get Opposite charges.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      Unlike attract.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      Unlike attract.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      attract

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    attract

    Copy onto your answer sheet — in this order

    Answer: attract

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  18. 18 · 2 Marks · Faraday’s law & Lenz

    Faraday’s law: ε=

    Formulas

    Φ=B A cos θ

    Magnetic flux

    ε=−N ΔΦΔt

    Faraday’s law

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Faraday’s law: ε =

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Faraday’s law: ε =. Circle that word — that is the missing variable.

    Find

    We are required to find: Faraday’s law: ε =. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: Induced emf equals minus the rate of change of flux linkage. Then substitute the given, one line at a time, to get Faraday’s law: ε =.

    In other words — as if you have never seen this before

    Induced emf equals minus the rate of change of flux linkage.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    Induced emf equals minus the rate of change of flux linkage.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Faraday’s law: ε =. Circle that word — that is the missing variable. Find: We are required to find: Faraday’s law: ε =. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: Induced emf equals minus the rate of change of flux linkage. Then substitute the given, one line at a time, to get Faraday’s law: ε =.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      Induced emf equals minus the rate of change of flux linkage.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      Induced emf equals minus the rate of change of flux linkage.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      −N ΔΦΔt

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    −N ΔΦΔt

    Copy onto your answer sheet — in this order

    Answer:−N ΔΦΔt

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  19. 19 · 2 Marks

    South African mains frequency is

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: South African mains frequency is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: South African mains frequency is. Circle that word — that is the missing variable.

    Find

    We are required to find: South African mains frequency is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: Eskom AC is 50 Hz; rms voltage 230 V. Then substitute the given, one line at a time, to get South African mains frequency is.

    In other words — as if you have never seen this before

    Eskom AC is 50 Hz; rms voltage 230 V.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    Eskom AC is 50 Hz; rms voltage 230 V.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: South African mains frequency is. Circle that word — that is the missing variable. Find: We are required to find: South African mains frequency is. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: Eskom AC is 50 Hz; rms voltage 230 V. Then substitute the given, one line at a time, to get South African mains frequency is.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      Eskom AC is 50 Hz; rms voltage 230 V.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      Eskom AC is 50 Hz; rms voltage 230 V.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      50 Hz

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    50 Hz

    Copy onto your answer sheet — in this order

    Answer: 50 Hz

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  20. 20 · 2 Marks

    Emf is measured when

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Emf is measured when

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Emf is measured when. Circle that word — that is the missing variable.

    Find

    We are required to find: Emf is measured when. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: ε is the open-circuit pd. Then substitute the given, one line at a time, to get Emf is measured when.

    In other words — as if you have never seen this before

    ε is the open-circuit pd.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    ε is the open-circuit pd.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Emf is measured when. Circle that word — that is the missing variable. Find: We are required to find: Emf is measured when. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: ε is the open-circuit pd. Then substitute the given, one line at a time, to get Emf is measured when.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      ε is the open-circuit pd.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      ε is the open-circuit pd.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      no current is drawn (open circuit)

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    no current is drawn (open circuit)

    Copy onto your answer sheet — in this order

    Answer: no current is drawn (open circuit)

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  21. 21 · 2 Marks · Vertical projectile motion

    A ball is thrown up at 20 ms. Time to top? (g = 10)

    uh

    Formulas

    Δy=vi Δt+½ a (Δt)²

    Vertical displacement

    Notes: u = 20 ms up. v = 0 at the top. a = −10 m·s⁻². Unknown: t.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: A ball is thrown up at 20 ms. Time to top? (g = 10)

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 20 ms · 10. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: (g = 10). Circle that word — that is the missing variable.

    Find

    We are required to find: (g = 10). Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write 0 = 20 − 10t with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives (g = 10).

    In other words — as if you have never seen this before

    v = u + at. At the top the vertical speed is zero, not the acceleration.

    2. What do we already know?

    u = 20 ms up. v = 0 at the top. a = −10 m·s⁻². Unknown: t.

    3. Which method — and why this one?

    v = u + at. At the top the vertical speed is zero, not the acceleration.

    4. Step-by-step working

    1. 01 / 05

      Write v = u + at

      0=20+(−10)t.

      0=20−10t

      Why this step: Write the formula before numbers. The memo awards a method mark even if a digit slips later.

    2. 02 / 05

      Solve

      10t=20→t=2 s.

      t=2 s

      Why this step: One job per line so you can find a slip, and so a marker can follow the marks.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      2 s

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    2 s

    Copy onto your answer sheet — in this order

    Formula: 0=20−10t

    Answer: 2 s

    6. Check it like a marker

    Height = ut + ½at² = 40 − 20 = 20 m. Sensible for a 20 ms throw.

    7. A trap first-timers fall into

    t = ug is right only if you remember a is negative. t = 20 is mixing units.

  22. 22 · 3 Marks · Work, energy & power

    A 4 kg box lifted 3 m at constant speed. Work against gravity (g=9.8)

    Formulas

    W=F Δx cosθ

    Work

    P=WΔt=F v

    Power

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: A 4 kg box lifted 3 m at constant speed. Work against gravity (g=9.8)

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 4 kg · 3 m · 9.8. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: 8). Circle that word — that is the missing variable.

    Find

    We are required to find: 8). Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: W=mgh=4×9. Then substitute the given, one line at a time, to get 8).

    In other words — as if you have never seen this before

    W=mgh=4×9.8×3.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 4 kg · 3 m · 9.8. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    W=mgh=4×9.8×3.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 4 kg · 3 m · 9.8. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: 8). Circle that word — that is the missing variable. Find: We are required to find: 8). Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: W=mgh=4×9. Then substitute the given, one line at a time, to get 8).

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 4 kg · 3 m · 9.8. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      W=mgh=4×9.8×3.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      W=mgh=4×9.8×3.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      117.6 J

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    117.6 J

    Copy onto your answer sheet — in this order

    Answer: 117.6 J

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  23. 23 · 4 Marks

    hf < W₀. Photoelectrons are

    Notes: Photon energy hf is smaller than the work function W₀ of the metal.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: hf < W₀. Photoelectrons are

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Photoelectrons are. Circle that word — that is the missing variable.

    Find

    We are required to find: Photoelectrons are. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write hf = W₀ + E_k with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives Photoelectrons are.

    In other words — as if you have never seen this before

    One photon talks to one electron. If that photon cannot pay W₀, a crowd of dim photons still cannot. Threshold is a hard cut-off.

    2. What do we already know?

    Photon energy hf is smaller than the work function W₀ of the metal.

    3. Which method — and why this one?

    One photon talks to one electron. If that photon cannot pay W₀, a crowd of dim photons still cannot. Threshold is a hard cut-off.

    4. Step-by-step working

    1. 01 / 05

      Einstein’s equation

      hf = W₀ + E_k. If hf < W₀ then E_k would be negative, which a kinetic energy cannot be. So no electron leaves.

      hf=W₀+Ek

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    2. 02 / 05

      Intensity is not a rescue

      Brighter light means more photons per second, each still too poor. Rate would rise only above threshold.

      Why this step: This is the experiment that killed the wave picture. Waves would pool energy; photons do not.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      not emitted

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    not emitted

    Copy onto your answer sheet — in this order

    Formula: hf=W₀+Ek

    Answer: not emitted

    6. Check it like a marker

    Below threshold: zero current, however bright. Above threshold: current rises with brightness, E_k rises with frequency.

    7. A trap first-timers fall into

    “Emitted if intensity is high.” That is the classical (wrong) prediction. NSC wants the photon picture.

  24. 24 · 4 Marks · Doppler effect

    Source moving away from a Durban listener. Observed f is

    λA

    Formulas

    fL=fs (v ± vL)(v ± vs)

    Doppler formula

    Notes: Source recedes. Listener at rest. Sound (or any wave) in air.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Source moving away from a Durban listener. Observed f is

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: no numbers yet — only a name, a diagram, or a worded unknown. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Observed f is. Circle that word — that is the missing variable.

    Find

    We are required to find: Observed f is. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write f_L = f_s v(v + v_s) with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives Observed f is.

    In other words — as if you have never seen this before

    Doppler: a receding source stretches the wavelength, so the pitch drops. In the NSC formula the plus sits in the denominator.

    2. What do we already know?

    Source recedes. Listener at rest. Sound (or any wave) in air.

    3. Which method — and why this one?

    Doppler: a receding source stretches the wavelength, so the pitch drops. In the NSC formula the plus sits in the denominator.

    4. Step-by-step working

    1. 01 / 05

      Picture the waves

      Crests are laid down further apart behind a moving source. Bigger λ, and v = fλ with v fixed, so f drops.

      Why this step: Ambulance going away sounds lower. Coming towards you it sounds higher. You already know this from the street.

    2. 02 / 05

      NSC sign memory

      f_L = f_s (v ± vL) / (v ± v_s). Source away: plus in the denominator, which makes f_L smaller.

      fL=fs v(v + vs)

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      lower than source f

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    lower than source f

    Copy onto your answer sheet — in this order

    Formula: fL=fs v(v + vs)

    Answer: lower than source f

    6. Check it like a marker

    Away → lower. Towards → higher. Stationary → equal. Zero would mean no wave at all.

    7. A trap first-timers fall into

    Mixing the listener and source signs. A moving listener towards the source also raises f, but that plus sits on the numerator.

  25. 25 · 4 Marks

    2 kg at +4 m·s⁻¹ collides inelastically and sticks to 2 kg at rest. Final v?

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: 2 kg at +4 m·s⁻¹ collides inelastically and sticks to 2 kg at rest. Final v?

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 2 kg · 4 m·s⁻¹ · 2 kg. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: Final v. Circle that word — that is the missing variable.

    Find

    We are required to find: Final v. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: m v = (2m) v_f. Then substitute the given, one line at a time, to get Final v.

    In other words — as if you have never seen this before

    m v=(2m) vf→vf=2 m·s⁻¹.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 2 kg · 4 m·s⁻¹ · 2 kg. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    m v=(2m) vf→vf=2 m·s⁻¹.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 2 kg · 4 m·s⁻¹ · 2 kg. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: Final v. Circle that word — that is the missing variable. Find: We are required to find: Final v. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: m v = (2m) v_f. Then substitute the given, one line at a time, to get Final v.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 2 kg · 4 m·s⁻¹ · 2 kg. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      m v=(2m) vf→vf=2 m·s⁻¹.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      m v=(2m) vf→vf=2 m·s⁻¹.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      2 m·s⁻¹

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    2 m·s⁻¹

    Copy onto your answer sheet — in this order

    Answer: 2 m·s⁻¹

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  26. 26 · 3 Marks

    Thrown up at 19.6 m·s⁻¹. Time to the top? (g = 9.8)

    Notes: v_i = +19.6 m·s⁻¹ (up positive). At the top v_f = 0. a = −9.8 m·s⁻². Unknown: t.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Thrown up at 19.6 m·s⁻¹. Time to the top? (g = 9.8)

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 19.6 m·s⁻¹ · 9.8. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: 8). Circle that word — that is the missing variable.

    Find

    We are required to find: 8). Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write v_f = v_i + a t with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives 8).

    In other words — as if you have never seen this before

    v_f = v_i + a t. The only unknown is t. Keep the minus on g.

    2. What do we already know?

    v_i = +19.6 m·s⁻¹ (up positive). At the top v_f = 0. a = −9.8 m·s⁻². Unknown: t.

    3. Which method — and why this one?

    v_f = v_i + a t. The only unknown is t. Keep the minus on g.

    4. Step-by-step working

    1. 01 / 05

      Write the equation

      0=19.6+(−9.8) t

      vf=vi+a t

      Why this step: If you drop the minus, 0 = 19.6 + 9.8 t gives a negative time — a loud sign-error alarm.

    2. 02 / 05

      Solve for t

      9.8 t = 19.6. t = 19.69.8=2 s. (19.6 is exactly 2 × 9.8.)

      t=2 s

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      2 s

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    2 s

    Copy onto your answer sheet — in this order

    Formula: vf=vi+a t

    Answer: 2 s

    6. Check it like a marker

    Hang time back to the thrower is 4 s. Max height would be v_avg × t = 9.8 × 2 = 19.6 m.

    7. A trap first-timers fall into

    Using Δy = v t with v = 19.6 the whole way. Speed is not constant — it falls to zero.

  27. 27 · 3 Marks

    N=50, ΔΦ=0.008 Wb, Δt=0.10 s. |ε|=

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: N=50, ΔΦ=0.008 Wb, Δt=0.10 s. |ε| =

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 50 · 0.008 Wb · 0.10 s. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: |ε| =. Circle that word — that is the missing variable.

    Find

    We are required to find: |ε| =. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: 50 × 0. Then substitute the given, one line at a time, to get |ε| =.

    In other words — as if you have never seen this before

    50×0.0080.10=4.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 50 · 0.008 Wb · 0.10 s. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    50×0.0080.10=4.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 50 · 0.008 Wb · 0.10 s. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: |ε| =. Circle that word — that is the missing variable. Find: We are required to find: |ε| =. Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: 50 × 0. Then substitute the given, one line at a time, to get |ε| =.

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 50 · 0.008 Wb · 0.10 s. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      50×0.0080.10=4.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      50×0.0080.10=4.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      4.0 V

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    4.0 V

    Copy onto your answer sheet — in this order

    Answer: 4.0 V

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  28. 28 · 3 Marks

    A step-down transformer has Ns < Np so Vs is

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: A step-down transformer has Ns < Np so Vs is

    In other words — as if you have never seen this before

    VsVp=NsNp.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    VsVp=NsNp.

    4. Step-by-step working

    1. 01 / 07

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 07

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: every number and its unit in the sentence. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    3. 03 / 07

      Step C — Name the method in words

      VsVp=NsNp.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    4. 04 / 07

      Working

      VsVp=NsNp.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    5. 05 / 07

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    6. 06 / 07

      Step F — Box the answer with its unit

      smaller than Vp

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    7. 07 / 07

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    smaller than Vp

    Copy onto your answer sheet — in this order

    Answer: smaller than Vp

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  29. 29 · 3 Marks

    Time of flight for a throw up and back, v_i=19.6 m·s⁻¹ (g=9.8)

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Time of flight for a throw up and back, v_i=19.6 m·s⁻¹ (g=9.8)

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 19.6 m·s⁻¹ · 9.8. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: 8). Circle that word — that is the missing variable.

    Find

    We are required to find: 8). Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    What we need to calculate: Up 2 s, down 2 s. Then substitute the given, one line at a time, to get 8).

    In other words — as if you have never seen this before

    Up 2 s, down 2 s.

    2. What do we already know?

    Copy these onto the left of your page, one per line, with units: 19.6 m·s⁻¹ · 9.8. Mixing cm with m, or minutes with seconds, loses a method mark.

    3. Which method — and why this one?

    Up 2 s, down 2 s.

    4. Step-by-step working

    1. 01 / 08

      Step A — Read the question twice

      Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    2. 02 / 08

      Step A2 — Hunt: Given, Missing, Find, Calculate

      Given: Numbers and units already in the sentence: 19.6 m·s⁻¹ · 9.8. Copy each one into a column. A name without a number is not given. Missing: After you copy the given, the letter that still has no number is missing. The paper is pointing at: 8). Circle that word — that is the missing variable. Find: We are required to find: 8). Write that as a symbol on the left, with a question mark, before you touch a formula. Calculate: What we need to calculate: Up 2 s, down 2 s. Then substitute the given, one line at a time, to get 8).

      Why this step: Do not name the letters yet. First hunt: what already has a number (Given), what has no number (Missing), the word the paper wants (Find), and which formula still contains the missing letter (Calculate).

    3. 03 / 08

      Step B — Write the given in a column

      Copy these onto the left of your page, one per line, with units: 19.6 m·s⁻¹ · 9.8. Mixing cm with m, or minutes with seconds, loses a method mark.

      Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

    4. 04 / 08

      Step C — Name the method in words

      Up 2 s, down 2 s.

      Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

    5. 05 / 08

      Working

      Up 2 s, down 2 s.

      Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

    6. 06 / 08

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    7. 07 / 08

      Step F — Box the answer with its unit

      4 s

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    8. 08 / 08

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    4 s

    Copy onto your answer sheet — in this order

    Answer: 4 s

    6. Check it like a marker

    Does your answer appear as one of the options? Do the units match what was asked (m, N, J, °)? If you put the number back into the original equation, does it still hold? Estimate: is the size sensible?

    7. A trap first-timers fall into

    First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

  30. 30 · 2 Marks

    E=hf. f=6×10¹⁴ Hz, h=6.6×10⁻³⁴. E?

    Notes: f = 6×10¹⁴ Hz. h = 6.6×10⁻³⁴ J·s. Unknown: photon energy E.

    How we got there

    Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

    Explain in another language · 11

    1. What is the question asking?

    Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: E = hf. f = 6×10¹⁴ Hz, h = 6.6×10⁻³⁴. E?

    Before any working — hunt first

    Given

    Numbers and units already in the sentence: 6 · 10¹ · 6.6 · 10⁻³. Copy each one into a column. A name without a number is not given.

    Missing

    After you copy the given, the letter that still has no number is missing. The paper is pointing at: E. Circle that word — that is the missing variable.

    Find

    We are required to find: E. Write that as a symbol on the left, with a question mark, before you touch a formula.

    Calculate

    Write E = hf with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives E.

    In other words — as if you have never seen this before

    E = hf. Do not divide. Keep scientific notation.

    2. What do we already know?

    f = 6×10¹⁴ Hz. h = 6.6×10⁻³⁴ J·s. Unknown: photon energy E.

    3. Which method — and why this one?

    E = hf. Do not divide. Keep scientific notation.

    4. Step-by-step working

    1. 01 / 05

      Write Planck

      E=h f.

      E=hf

      Why this step: Write the formula before numbers. The memo awards a method mark even if a digit slips later.

    2. 02 / 05

      Multiply

      6.6×10⁻³⁴×6×10¹⁴=39.6×10⁻²⁰=3.96×10⁻¹⁹ ≈ 4.0×10⁻¹⁹ J.

      E=4.0×10⁻¹⁹ J

      Why this step: One job per line so you can find a slip, and so a marker can follow the marks.

    3. 03 / 05

      Step G — Sense-check the size

      Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

      Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

    4. 04 / 05

      Step F — Box the answer with its unit

      4.0×10⁻¹⁹ J

      Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

    5. 05 / 05

      Step H — What the marker is looking for

      On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

      Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

    5. The answer

    4.0×10⁻¹⁹ J

    Copy onto your answer sheet — in this order

    Formula: E=hf

    Answer: 4.0×10⁻¹⁹ J

    6. Check it like a marker

    Order of magnitude 10⁻¹⁹ J is a visible photon. 10⁻⁴⁸ would be nonsense.

    7. A trap first-timers fall into

    E = hf is the reciprocal. The paper wrote E = hf on the formula sheet.

Ntsako · fx-991ZA PLUS. Tap to calculate.