# Mechanics Sample Questions (force and motion)

Some questions from past papers in word document. Contains the mark scheme as well. Originally for OCR physics.

HideShow resource information
• Created by: Nicole
• Created on: 18-01-11 19:45

First 150 words of the document:

Force and Motion Questions. From past papers/with mark scheme.
1. (a) Distinguish between a scalar quantity and a vector quantity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b) A car travels one complete lap around a circular track at an average speed of
100 km h­1.
(i) If the lap takes 3.0 minutes, show that the length of the track is 5.0 km.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(ii) What is the magnitude of displacement of the car after 1.5 minutes?
...........................................................................................................................
(4)
(Total 6 marks)
2. The diagram shows a straight, horizontal swimming bath spring board of length 4.00m and of weight 300
N. It is freely hinged at A and rests on a roller B, where AB is 1.60m. A boy of weight 400N stands at
end C.
(a) On the diagram show the directions of the forces acting on the board at A and B.
(2)

## Other pages in this set

### Page 2

Here's a taster:

Calculate the magnitudes of the forces
(i) at A ...................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(ii) at B ...................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 6 marks)
3. A ball is dropped and rebounds vertically to less than the original height.…read more

### Page 3

Here's a taster:

The ball is then thrown at an angle to the horizontal and follows the trajectory shown in the
diagram.
Mark on the diagram the directions of
(i) the acceleration vector at P,
(ii) the acceleration vector at Q,
(iii) the momentum vector at P,
(iv) the momentum vector at Q.…read more

### Page 4

Here's a taster:

The mass of the ball is 0.15 kg and the initial direction makes an angle of 50° to the horizontal.
Calculate the magnitude of the momentum of the ball at Q when it is projected with an initial speed
of 15 m s­1. Neglect the effects of air resistance.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(4)
(Total 13 marks)
4. A solid iron ball of mass 890 kg is used on a demolition site. It hangs from the jib of a crane suspended by

### Page 5

Here's a taster:

Total 9 marks)
5. (a) What do you understand by the principle of conservation of energy?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b) (i) Explain how the principle of conservation of energy applies to a man sliding from rest
down a vertical pole, if there is a constant resistive force opposing the motion.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(ii) The man starts sliding at time t = 0 and reaches the ground at time t.…read more

### Page 6

Here's a taster:

A domestic kettle is marked 250V, 2.3 kW and the manufacturer claims that it will heat a pint of
cold water to boiling point in 94s.
specific heat capacity of water = 4.2 × 103 J kg­1 K­1
specific latent heat of vaporisation of water = 2.3 × 106 J kg­1 K­1
density of water = 1000 kg m­3
1 pint = 5.7 × 10­4 m3
(i) Test this claim by calculation and state any simplifying assumptions that you make.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................

### Page 7

Here's a taster:

A ball of mass 0.12 kg strikes a stationary cricket bat with a speed of 18ms­1. The ball is in
contact with the bat for 0.14 s and returns along its original path with a speed of 15 ms­1.
Calculate
(i) the momentum of the ball before the collision,
...........................................................................................................................
...........................................................................................................................
(ii) the momentum of the ball after the collision,
...........................................................................................................................
...........................................................................................................................
(iii) the total change of momentum of the ball,
...........................................................................................................................

### Page 8

Here's a taster:

The diagram shows a gymnast of weight 720N hanging centrally from two rings, each attached to cables
which hang vertically.
(a) State the tension in each cable.
....................................................................................................................................
(1)
(b) The diagram shows the gymnast after he has raised his body so that his centre of mass moves
through a vertical distance of 0.60 m.…read more

### Page 9

Here's a taster:

Calculate
(i) the increase in gravitational potential energy of the gymnast,
..........................................................................................................................
..........................................................................................................................
(ii) the tension in each cable.
..........................................................................................................................
..........................................................................................................................
(3)
(c) The gymnast now raises his legs so that they become horizontal, without raising the rest of his body.
State and explain whether his gravitational potential energy is changed by this manoeuvre.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 6 marks)
8. The diagram shows a car travelling at a constant velocity along a horizontal road.…read more

### Page 10

Here's a taster:

The car has an effective power output of l8kW and is travelling at a constant velocity of 10 m s .
Show that the total resistive force acting is 1800 N.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
(c) The total resistive force consists of two components. One of these is a constant frictional force of
250 N and the other is the force of air resistance, which is proportional to the square of the car's