1.
State what is meant by a scalar.
[1 mark]
- magnitude only
JD SCIENCE
P2 Forces
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 a vector.
[1 mark]
- magnitude and direction
3.
State what is meant by Newton's first law.
[1 mark]
- resultant force 0 means constant velocity
4.
State what is meant by Newton's second law.
[1 mark]
- F = ma
5.
State what is meant by Newton's third law.
[1 mark]
- equal and opposite forces on two different objects
6.
State what is meant by weight.
[1 mark]
- gravitational force
7.
State what is meant by stopping distance.
[1 mark]
- thinking + braking
8.
State what is meant by momentum.
[1 mark]
- p = mv
9.
State what is meant by Hooke's law.
[1 mark]
- F = ke, up to the limit of proportionality
10.
State what is meant by a moment.
[1 mark]
- turning effect of a force
11.
Grace is asked about a scalar in a OCR Physics paper.
(a) [2 marks]
- mass, speed, distance, energy
(b) [3 marks]
- no direction
12.
Grace is asked about a vector in a OCR Physics paper.
(a) [2 marks]
- force, velocity, acceleration, displacement
(b) [3 marks]
- shown by arrows
13.
Grace is asked about Newton's first law in a OCR Physics paper.
(a) [2 marks]
- including rest
(b) [3 marks]
- balanced forces
14.
Grace is asked about Newton's second law in a OCR Physics paper.
(a) [2 marks]
- resultant force
(b) [3 marks]
- in newtons
15.
Grace is asked about Newton's third law in a OCR Physics paper.
(a) [2 marks]
- same type
(b) [3 marks]
- not balanced forces on one object
16.
Grace is asked about weight in a OCR Physics paper.
(a) [2 marks]
- W = mg
(b) [3 marks]
- newtons, not kg
17.
W = mg. 60 kg, g=10
[3 marks]
- Final answer: 600 N
18.
F = ma. 4 kg, 3 m/s²
[3 marks]
- Final answer: 12 N
19.
a = Δv/t. 0 to 20 m/s in 8 s
[3 marks]
- Final answer: 2.5 m/s²
20.
p = mv. 0.2 kg at 15 m/s
[3 marks]
- Final answer: 3 kg m/s
21.
F = ke. k=40 N/m, e=0.05 m
[3 marks]
- Final answer: 2 N
22.
Thinking distance at 15 m/s if reaction time is 0.6 s
[3 marks]
- Final answer: 9 m
23.
Grace carries out a OCR-style required practical linked to forces and motion. 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 forces and motion. 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 forces and motion. 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 forces and motion. 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 a scalar with a vector.
[4 marks]
- magnitude only
- magnitude and direction
- give one linked difference
28.
Compare a vector with Newton's first law.
[4 marks]
- magnitude and direction
- resultant force 0 means constant velocity
- give one linked difference
29.
Compare Newton's first law with Newton's second law.
[4 marks]
- resultant force 0 means constant velocity
- F = ma
- give one linked difference
30.
Compare Newton's second law with Newton's third law.
[4 marks]
- F = ma
- equal and opposite forces on two different objects
- give one linked difference
31.
Apply your knowledge of stopping distance to this situation: affected by speed, tiredness, road, brakes
[3 marks]
- affected by speed, tiredness, road, brakes
32.
Apply your knowledge of momentum to this situation: conserved in a closed system
[3 marks]
- conserved in a closed system