Open marking scheme and model answers
Attempt the paper before opening the key. Multi-mark answers show expected principles and results; award partial credit for valid intermediate steps.
Q1 · 1 mark
Seven.
Suggested allocation by section: 1-mark questions earn one mark for the correct fact, formula or unit; 2-mark questions normally award one mark for the principle/formula and one for the explanation or result; 3-mark questions award credit for the relation, working/reasoning and result with unit; 4-mark questions award credit for the principle, equation, working and final answer/interpretation. Accept equivalent correct methods.
Q2 · 1 mark
kelvin (K).
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q3 · 1 mark
Three.
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Q4 · 1 mark
[LT⁻¹].
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q5 · 1 mark
[MLT⁻²].
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q6 · 1 mark
Yes.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q7 · 1 mark
No.
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Q8 · 1 mark
pascal (Pa).
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Q9 · 2 marks
12.5.
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Q10 · 2 marks
[MLT⁻¹].
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q11 · 2 marks
ut and at² both have dimension L; homogeneous.
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Q12 · 2 marks
20 m s⁻¹.
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Q13 · 2 marks
Four.
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Q14 · 2 marks
Both are [ML²T⁻²].
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Q15 · 3 marks
Equating dimensions gives a=½, b=−½, so T∝√(l/g).
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q16 · 3 marks
4πr³/3=33.5 cm³.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q17 · 3 marks
[M⁻¹L³T⁻²].
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Q18 · 3 marks
51.68 cm² rounds to 52 cm².
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Q19 · 4 marks
a=½, b=−½; T∝√(m/k).
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.
Q20 · 4 marks
18.2 cm³; extra digits are unsupported.
Suggested credit: award marks for the correct principle, working and result as applicable; accept equivalent correct methods.