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: Impulse equals
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: Impulse equals. Circle that word — that is the missing variable.
Find
We are required to find: Impulse equals. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
What we need to calculate: FΔt = Δp. Then substitute the given, one line at a time, to get Impulse equals.
In other words — as if you have never seen this before
If you have never seen this before: FΔt = Δp. Impulse is the area under an F–t graph and it equals the change in momentum. 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?
FΔt = Δp. Impulse is the area under an F–t graph and it equals the change in momentum.
4. Step-by-step working
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.
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: Impulse equals. Circle that word — that is the missing variable.
Find: We are required to find: Impulse equals. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: What we need to calculate: FΔt = Δp. Then substitute the given, one line at a time, to get Impulse equals.
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).
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.
04 / 08
Step C — Name the method in words
FΔt = Δp. Impulse is the area under an F–t graph and it equals the change in momentum.
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.
05 / 08
Working
FΔt = Δp. Impulse is the area under an F–t graph and it equals the change in momentum.
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.
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.
07 / 08
Step F — Box the answer with its unit
change in momentum
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.
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
change in momentum
Copy onto your answer sheet — in this order
Answer: change in momentum
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…”
1.2 · 12 Marks
Thrown up at 19.6 m·s⁻¹. Max height? (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 19.6 m·s⁻¹. Max height? (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: v² = u² + 2aΔy. Then substitute the given, one line at a time, to get 8).
In other words — as if you have never seen this before
If you have never seen this before: v² = u² + 2aΔy → 0 = (19.6)² + 2(−9.8)Δy → Δy = 19.6 m. Or v_avg × t with t = 2 s. 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: 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?
v² = u² + 2aΔy → 0 = (19.6)² + 2(−9.8)Δy → Δy = 19.6 m. Or v_avg × t with t = 2 s.
4. Step-by-step working
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.
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: v² = u² + 2aΔy. 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).
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.
04 / 08
Step C — Name the method in words
v² = u² + 2aΔy → 0 = (19.6)² + 2(−9.8)Δy → Δy = 19.6 m. Or v_avg × t with t = 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.
05 / 08
Working
v² = u² + 2aΔy → 0 = (19.6)² + 2(−9.8)Δy → Δy = 19.6 m. Or v_avg × t with 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.
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.
07 / 08
Step F — Box the answer with its unit
19.6 m
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.
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
19.6 m
Copy onto your answer sheet — in this order
Answer: 19.6 m
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 · 14 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: Doppler: receding source stretches the waves, pitch drops. 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: Doppler: receding source stretches the waves, pitch drops. Plus sign in the denominator of the NSC formula. 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?
Doppler: receding source stretches the waves, pitch drops. Plus sign in the denominator of the NSC formula.
4. Step-by-step working
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.
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: Doppler: receding source stretches the waves, pitch drops. 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).
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.
04 / 08
Step C — Name the method in words
Doppler: receding source stretches the waves, pitch drops. Plus sign in the denominator of the NSC formula.
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.
05 / 08
Working
Doppler: receding source stretches the waves, pitch drops. Plus sign in the denominator of the NSC formula.
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.
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.
07 / 08
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.
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 than source f
Copy onto your answer sheet — in this order
Answer: lower 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…”
2.2 · 14 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: V_max = V_rms × √2 ≈ 230 × 1. 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: V_max = V_rms × √2 ≈ 230 × 1.414 ≈ 325 V. RMS is not the peak; do not leave it as 230. 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?
V_max = V_rms × √2 ≈ 230 × 1.414 ≈ 325 V. RMS is not the peak; do not leave it as 230.
4. Step-by-step working
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.
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: V_max = V_rms × √2 ≈ 230 × 1. 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).
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.
04 / 08
Step C — Name the method in words
V_max = V_rms × √2 ≈ 230 × 1.414 ≈ 325 V. RMS is not the peak; do not leave it as 230.
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.
05 / 08
Working
V_max = V_rms × √2 ≈ 230 × 1.414 ≈ 325 V. RMS is not the peak; do not leave it as 230.
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.
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.
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.
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…”
3.1 · 15 Marks
hf < W₀. Electrons are
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. Electrons 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: Electrons are. Circle that word — that is the missing variable.
Find
We are required to find: Electrons are. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
What we need to calculate: Each photon acts alone. Then substitute the given, one line at a time, to get Electrons are.
In other words — as if you have never seen this before
If you have never seen this before: Each photon acts alone. If one photon cannot pay the work function, a crowd of dim photons still cannot. Threshold is a hard cut-off. 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?
Each photon acts alone. If one photon cannot pay the work function, a crowd of dim photons still cannot. Threshold is a hard cut-off.
4. Step-by-step working
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.
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: Electrons are. Circle that word — that is the missing variable.
Find: We are required to find: Electrons are. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: What we need to calculate: Each photon acts alone. Then substitute the given, one line at a time, to get Electrons are.
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).
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.
04 / 08
Step C — Name the method in words
Each photon acts alone. If one photon cannot pay the work function, a crowd of dim photons still cannot. Threshold is a hard cut-off.
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.
05 / 08
Working
Each photon acts alone. If one photon cannot pay the work function, a crowd of dim photons still cannot. Threshold is a hard cut-off.
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.
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.
07 / 08
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.
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
not emitted
Copy onto your answer sheet — in this order
Answer: not emitted
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 · 15 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: W = F Δx cosθ = 80 × 5 × cos 60° = 400 × 0. 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
If you have never seen this before: W = F Δx cosθ = 80 × 5 × cos 60° = 400 × 0.5 = 200 J. The cosine picks only the component along the displacement. 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: 80 N · 5 m · 60°. Mixing cm with m, or minutes with seconds, loses a method mark.
3. Which method — and why this one?
W = F Δx cosθ = 80 × 5 × cos 60° = 400 × 0.5 = 200 J. The cosine picks only the component along the displacement.
4. Step-by-step working
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.
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: W = F Δx cosθ = 80 × 5 × cos 60° = 400 × 0. 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).
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.
04 / 08
Step C — Name the method in words
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: 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.
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.
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.
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.
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…”
7 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
8 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
9 · 2 Marks · Work, energy & power
SI unit of power is the
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: SI unit of power is the
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: SI unit of power is the. Circle that word — that is the missing variable.
Find
We are required to find: SI unit of power is the. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
What we need to calculate: W = J·s⁻¹. Then substitute the given, one line at a time, to get SI unit of power is the.
In other words — as if you have never seen this before
W=J·s⁻¹.
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?
W=J·s⁻¹.
4. Step-by-step working
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.
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: SI unit of power is the. Circle that word — that is the missing variable.
Find: We are required to find: SI unit of power is the. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: What we need to calculate: W = J·s⁻¹. Then substitute the given, one line at a time, to get SI unit of power is the.
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).
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.
04 / 08
Step C — Name the method in words
W=J·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.
05 / 08
Working
W=J·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.
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.
07 / 08
Step F — Box the answer with its unit
watt
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.
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
watt
Copy onto your answer sheet — in this order
Answer: watt
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 · 4 Marks · Doppler effect
Source moving away from a Durban listener. Observed f is
Doppler effect
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
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.
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.
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.
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.
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.
11 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
12 · 4 Marks
A transformer Np=500, Ns=100, Vp=230 V. Vs=
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 transformer Np=500, Ns=100, Vp=230 V. Vs =
Before any working — hunt first
Given
Numbers and units already in the sentence: 500 · 100 · 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: Vs =. Circle that word — that is the missing variable.
Find
We are required to find: Vs =. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
What we need to calculate: VsVp=NsNp. Then substitute the given, one line at a time, to get Vs =.
In other words — as if you have never seen this before
VsVp=NsNp→Vs=230×100500=46 V.
2. What do we already know?
Copy these onto the left of your page, one per line, with units: 500 · 100 · 230 V. Mixing cm with m, or minutes with seconds, loses a method mark.
3. Which method — and why this one?
VsVp=NsNp→Vs=230×100500=46 V.
4. Step-by-step working
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.
02 / 08
Step A2 — Hunt: Given, Missing, Find, Calculate
Given: Numbers and units already in the sentence: 500 · 100 · 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: Vs =. Circle that word — that is the missing variable.
Find: We are required to find: Vs =. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: What we need to calculate: VsVp=NsNp. Then substitute the given, one line at a time, to get Vs =.
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).
03 / 08
Step B — Write the given in a column
Copy these onto the left of your page, one per line, with units: 500 · 100 · 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.
04 / 08
Step C — Name the method in words
VsVp=NsNp→Vs=230×100500=46 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.
05 / 08
Working
VsVp=NsNp→Vs=230×100500=46 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.
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.
07 / 08
Step F — Box the answer with its unit
46 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.
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
46 V
Copy onto your answer sheet — in this order
Answer: 46 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…”
13 · 2 Marks · Momentum & impulse
Momentum of 2 kg at 3 m·s⁻¹ is
Momentum & impulse
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
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.
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).
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.
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.
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.
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.
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.
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…”
14 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
15 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
16 · 2 Marks · Work, energy & power
Work to lift 10 kg through 2 m (g = 10)
Formulas
W=F Δx cosθ
Work
P=WΔt=F v
Power
Notes: m = 10 kg. Δh = 2 m. g = 10. Lifted slowly, ΔK = 0.
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 to lift 10 kg through 2 m (g = 10)
Before any working — hunt first
Given
Numbers and units already in the sentence: 10 kg · 2 m · 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: Work to lift 10 kg through 2 m (g = 10). Circle that word — that is the missing variable.
Find
We are required to find: Work to lift 10 kg through 2 m (g = 10). Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
Write W = mgh with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives Work to lift 10 kg through 2 m (g = 10).
In other words — as if you have never seen this before
W = ΔEp = mgh when you lift against gravity.
2. What do we already know?
m = 10 kg. Δh = 2 m. g = 10. Lifted slowly, ΔK = 0.
3. Which method — and why this one?
W = ΔEp = mgh when you lift against gravity.
4. Step-by-step working
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.
02 / 08
Step A2 — Hunt: Given, Missing, Find, Calculate
Given: Numbers and units already in the sentence: 10 kg · 2 m · 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: Work to lift 10 kg through 2 m (g = 10). Circle that word — that is the missing variable.
Find: We are required to find: Work to lift 10 kg through 2 m (g = 10). Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: Write W = mgh with empty letters. Cross out every letter that already has a number. Calculate the letter that is still standing — that gives Work to lift 10 kg through 2 m (g = 10).
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).
03 / 08
Step B — Write the given in a column
m = 10 kg. Δh = 2 m. g = 10. Lifted slowly, ΔK = 0.
Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.
04 / 08
Step C — Name the method in words
W = ΔEp = mgh when you lift against gravity.
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.
05 / 08
Write mgh
W=10×10×2=200 J.
W=mgh
Why this step: Write the formula before numbers. The memo awards a method mark even if a digit slips later.
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.
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.
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
Formula: W=mgh
Answer: 200 J
6. Check it like a marker
A 100 N weight through 2 m is 200 J. Matches.
7. A trap first-timers fall into
W = mgh is not work.
17 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
18 · 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
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.
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.
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.
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.
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.
19 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
20 · 3 Marks · Work, energy & power
If the threshold f₀ doubles, work function W₀
Formulas
W=F Δx cosθ
Work
P=WΔt=F v
Power
Notes: W₀=h f₀. f₀→2 f₀.
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: If the threshold f₀ doubles, work function W₀
In other words — as if you have never seen this before
Work function is linear in threshold frequency.
2. What do we already know?
W₀=h f₀. f₀→2 f₀.
3. Which method — and why this one?
Work function is linear in threshold frequency.
4. Step-by-step working
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.
02 / 07
Step B — Write the given in a column
W₀=h f₀. f₀→2 f₀.
Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.
03 / 07
Step C — Name the method in words
Work function is linear in threshold frequency.
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.
04 / 07
Scale
W₀'=h(2f₀)=2 W₀.
W₀=hf₀
Why this step: Write the formula before numbers. The memo awards a method mark even if a digit slips later.
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.
06 / 07
Step F — Box the answer with its unit
doubles
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.
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
doubles
Copy onto your answer sheet — in this order
Formula: W₀=hf₀
Answer: doubles
6. Check it like a marker
A metal that needs bluer light has a bigger W₀.
7. A trap first-timers fall into
Inverse-square thinking does not belong here — no r in Planck’s law.
21 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
22 · 3 Marks
E midway between equal like charges 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: E midway between equal like charges 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: E midway between equal like charges is. Circle that word — that is the missing variable.
Find
We are required to find: E midway between equal like charges is. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
What we need to calculate: Equal opposite field vectors cancel. Then substitute the given, one line at a time, to get E midway between equal like charges is.
In other words — as if you have never seen this before
Equal opposite field vectors cancel.
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?
Equal opposite field vectors cancel.
4. Step-by-step working
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.
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: E midway between equal like charges is. Circle that word — that is the missing variable.
Find: We are required to find: E midway between equal like charges is. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: What we need to calculate: Equal opposite field vectors cancel. Then substitute the given, one line at a time, to get E midway between equal like charges 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).
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.
04 / 08
Step C — Name the method in words
Equal opposite field vectors cancel.
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.
05 / 08
Working
Equal opposite field vectors cancel.
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.
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.
07 / 08
Step F — Box the answer with its unit
zero
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.
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
zero
Copy onto your answer sheet — in this order
Answer: zero
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 · 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
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.
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.
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.
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.
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.
24 · 3 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: increases. 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
increases
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?
increases
4. Step-by-step working
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.
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: increases. 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).
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.
04 / 08
Step C — Name the method in words
increases
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.
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.
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.
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.
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…”
25 · 2 Marks · Vertical projectile motion
A ball is thrown up at 20 ms. Time to top? (g = 10)
Vertical projectile motion
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
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.
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.
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.
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.
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.
26 · 4 Marks · Momentum & impulse
Elastic collision conserves
Momentum & impulse
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: Elastic collision conserves
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: Elastic collision conserves. Circle that word — that is the missing variable.
Find
We are required to find: Elastic collision conserves. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
What we need to calculate: Inelastic: momentum yes, E_k no. Then substitute the given, one line at a time, to get Elastic collision conserves.
In other words — as if you have never seen this before
Inelastic: momentum yes, E_k no.
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?
Inelastic: momentum yes, E_k no.
4. Step-by-step working
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.
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: Elastic collision conserves. Circle that word — that is the missing variable.
Find: We are required to find: Elastic collision conserves. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: What we need to calculate: Inelastic: momentum yes, E_k no. Then substitute the given, one line at a time, to get Elastic collision conserves.
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).
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.
04 / 08
Step C — Name the method in words
Inelastic: momentum yes, E_k no.
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.
05 / 08
Working
Inelastic: momentum yes, E_k no.
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.
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.
07 / 08
Step F — Box the answer with its unit
both momentum and E_k
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.
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
both momentum and E_k
Copy onto your answer sheet — in this order
Answer: both momentum and E_k
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…”
27 · 2 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: 4 kg·m·s⁻¹. 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
4 kg·m·s⁻¹
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?
4 kg·m·s⁻¹
4. Step-by-step working
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.
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: 4 kg·m·s⁻¹. 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).
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.
04 / 08
Step C — Name the method in words
4 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.
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.
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.
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.
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…”
28 · 3 Marks · Work, energy & power
If hf < W₀, photoelectrons
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: If hf < W₀, photoelectrons
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 hf < W₀, photoelectrons. Circle that word — that is the missing variable.
Find
We are required to find: If hf < W₀, photoelectrons. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate
What we need to calculate: Photon energy must at least equal the work function. Then substitute the given, one line at a time, to get If hf < W₀, photoelectrons.
In other words — as if you have never seen this before
Photon energy must at least equal the work function.
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?
Photon energy must at least equal the work function.
4. Step-by-step working
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.
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 hf < W₀, photoelectrons. Circle that word — that is the missing variable.
Find: We are required to find: If hf < W₀, photoelectrons. Write that as a symbol on the left, with a question mark, before you touch a formula.
Calculate: What we need to calculate: Photon energy must at least equal the work function. Then substitute the given, one line at a time, to get If hf < W₀, photoelectrons.
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).
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.
04 / 08
Step C — Name the method in words
Photon energy must at least equal the work function.
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.
05 / 08
Working
Photon energy must at least equal the work function.
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.
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.
07 / 08
Step F — Box the answer with its unit
are 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.
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
are not emitted
Copy onto your answer sheet — in this order
Answer: are not emitted
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 · 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
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.
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).
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.
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.
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.
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.
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.
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…”
30 · 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
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.
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.
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.
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.
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.