AQA A-Level Physics (7408)
A-Level Physics
Answer sheet
Mechanics and materials
Separate mark scheme — do not issue with the student worksheet
Time guide: — · Questions: 32 · Total marks: 104
Written in AQA A-Level style. Use the data and formulae booklet. Show substitution.
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
1. State what is meant by suvat.
[1 mark]
- constant acceleration equations
2. State what is meant by projectile motion.
[1 mark]
- horizontal u constant, vertical acceleration g
3. State what is meant by moments.
[1 mark]
- force × perpendicular distance
4. State what is meant by density and pressure.
5. State what is meant by Young modulus.
[1 mark]
- stress/strain in the linear region
6. State what is meant by stress and strain.
7. State what is meant by energy stored in a spring.
8. State what is meant by terminal velocity.
[1 mark]
- drag = weight (and upthrust)
9. State what is meant by resolving vectors.
10. State what is meant by centre of mass.
[1 mark]
- point where the weight acts
11. Amira is asked about suvat in a AQA Physics paper.
(b) [3 marks]
- take a direction as positive
12. Amira is asked about projectile motion in a AQA Physics paper.
(a) [2 marks]
- time from vertical motion
13. Amira is asked about moments in a AQA Physics paper.
(a) [2 marks]
- equilibrium: net force and net moment zero
14. Amira is asked about density and pressure in a AQA Physics paper.
15. Amira is asked about Young modulus in a AQA Physics paper.
16. Amira is asked about stress and strain in a AQA Physics paper.
(a) [2 marks]
- elastic if returns to original
17. s = ut + ½at². u=0, a=10, t=3
18. Range: ux=12, t=2.0 s
19. Stress if F=80 N, A=0.50×10⁻⁶ m²
[3 marks]
- Final answer: 1.6 × 10⁸ Pa
20. Strain if ΔL=0.40 mm, L=2.0 m
21. E = stress/strain from those values
[3 marks]
- Final answer: 8.0 × 10¹¹ Pa
23. Amira carries out a AQA-style required practical linked to mechanics and materials. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24. Amira carries out collecting valid data for mechanics and materials. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25. Amira carries out drawing a graph for mechanics and materials. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26. Amira carries out evaluating a method about mechanics and materials. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
27. Compare suvat with projectile motion.
[4 marks]
- constant acceleration equations
- horizontal u constant, vertical acceleration g
- give one linked difference
28. Compare projectile motion with moments.
[4 marks]
- horizontal u constant, vertical acceleration g
- force × perpendicular distance
- give one linked difference
29. Compare moments with density and pressure.
[4 marks]
- force × perpendicular distance
- ρ=m/V, P=F/A, P=ρgh
- give one linked difference
30. Compare density and pressure with Young modulus.
[4 marks]
- ρ=m/V, P=F/A, P=ρgh
- stress/strain in the linear region
- give one linked difference
31. Apply your knowledge of energy stored in a spring to this situation: area under F–x
32. Apply your knowledge of terminal velocity to this situation: resultant zero