1.
State what is meant by suvat.
[1 mark]
- constant acceleration equations
JD SCIENCE
Module 3 Forces and motion
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
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.
[1 mark]
- ρ=m/V, P=F/A, P=ρgh
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.
[1 mark]
- F/A and ΔL/L
7.
State what is meant by energy stored in a spring.
[1 mark]
- ½Fe or ½ke²
8.
State what is meant by terminal velocity.
[1 mark]
- drag = weight (and upthrust)
9.
State what is meant by resolving vectors.
[1 mark]
- components Fx = F cosθ
10.
State what is meant by centre of mass.
[1 mark]
- point where the weight acts
11.
Grace is asked about suvat in a OCR Physics paper.
(a) [2 marks]
- vectors along a line
(b) [3 marks]
- take a direction as positive
12.
Grace is asked about projectile motion in a OCR Physics paper.
(a) [2 marks]
- time from vertical motion
(b) [3 marks]
- range = uₓ t
13.
Grace is asked about moments in a OCR Physics paper.
(a) [2 marks]
- equilibrium: net force and net moment zero
(b) [3 marks]
- couples
14.
Grace is asked about density and pressure in a OCR Physics paper.
(a) [2 marks]
- fluids
(b) [3 marks]
- upthrust
15.
Grace is asked about Young modulus in a OCR Physics paper.
(a) [2 marks]
- E = (F/A)/(ΔL/L)
(b) [3 marks]
- property of the material
16.
Grace is asked about stress and strain in a OCR Physics paper.
(a) [2 marks]
- elastic if returns to original
(b) [3 marks]
- plastic beyond yield
17.
s = ut + ½at². u=0, a=10, t=3
[3 marks]
- Final answer: 45 m
18.
Range: ux=12, t=2.0 s
[3 marks]
- Final answer: 24 m
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
[3 marks]
- Final answer: 2.0 × 10⁻⁴
21.
E = stress/strain from those values
[3 marks]
- Final answer: 8.0 × 10¹¹ Pa
22.
½ke². k=200, e=0.050
[3 marks]
- Final answer: 0.25 J
23.
Grace carries out a OCR-style required practical linked to mechanics and materials. This is a typical OCR 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.
Grace carries out collecting valid data for mechanics and materials. This is a typical OCR 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.
Grace carries out drawing a graph for mechanics and materials. This is a typical OCR 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.
Grace carries out evaluating a method about mechanics and materials. This is a typical OCR 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
(c) [2 marks]
- too few repeats
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
[3 marks]
- area under F–x
32.
Apply your knowledge of terminal velocity to this situation: resultant zero
[3 marks]
- resultant zero