SECTION A
Multiple-choice questions
Each carry 1 mark
Instruction: Tick the right answer or cross to reject it.
1. Physical quantities can be classed as vectors or as scalars.
Which pair of quantities consists of two vectors?
A
B
C
D
kinetic energy and force
momentum and time
velocity and electric field strength
weight and temperature
2. Two dogs pull a sledge along an icy track, as shown.
Dog X pulls with a force of 200 N at an angle of 65° to the front edge of the sledge. Dog Y
pulls with a force of 120 N at an angle of 45° to the front edge of the sledge.
What is the resultant forward force on the sledge exerted by the two dogs?
A 80 N
B 170 N
C 270 N
D 320 N
3. In which example is it not possible for the underlined body to be in equilibrium?
A
B
C
D
An aeroplane climbs at a steady rate.
An aeroplane tows a glider at a constant altitude.
A speedboat changes direction at a constant speed.
Two boats tow a ship into harbour
4. The velocity-time graph for an object is shown.
A area 1 – area 2
B
𝐚𝐫𝐞𝐚 𝟏+𝐚𝐫𝐞𝐚 𝟐
(
𝟐
)
C area 1 + area 2
D area 2 – area 1
5. A girl throws a ball vertically upwards. It takes a time of 3.20 s to return to her hand.
Assume air resistance is negligible.
What is the initial speed with which the ball is thrown?
A 3.07 m s-1 B 7.85 m s-1 C 15.7 m s-1 D 31.4 m s-1
6. The sides of a cube are measured with calipers.
The measured length of each side is (30.0 ± 0.1) mm.
The measurements are used to calculate the volume of the cube.
What is the percentage uncertainty in the calculated value of the volume?
A 0.01%
B 0.3%
C 1%
D 3%
7. The momentum of a car of mass m increases from 𝑝1 to 𝑝2 .
What is the increase in the kinetic energy of the car?
8. The density of paper is 800 kgm-3. A typical sheet of paper has a width of 210 mm and a length
of 300 mm. The thickness of a pack of 500 sheets of paper is 50 mm.
What is the mass of a single sheet of paper?
A 0.5 g
B5g
C 50 g
D 500 g
9. The diagram shows four forces applied to a circular object.
10. A tennis ball falls freely, in air, from the top of a tall building.
Which graph best represents the variation with time t of the distance s fallen?
SECTION B
Answer all questions
1. (a) Define force.
..................................................................................................................................................[1]
(b) State the SI base units of force.
..................................................................................................................................................[1]
(c) The force F between two point charges is given by
𝐹=
𝑄1 𝑄2
4𝜋𝑟 2 𝜀
where 𝑄1 and 𝑄2 are the charges,
r is the distance between the charges,
𝜀 is a constant that depends on the medium between the charges.
Use the above expression to determine the base units of 𝜀.
base units ...........................................................[2]
[Total: 4]
2. (a) State the principle of conservation of momentum.
.......................................................................................................................................................
………….......................................................................................................................................
..................................................................................................................................................[2]
(b) A stationary firework explodes into three different fragments that move in a horizontal
plane, as illustrated in Fig. 2.1.
The fragment of mass 3.0M has a velocity of 7.0ms-1 perpendicular to line AB.
The fragment of mass 2.0M has a velocity of 6.0ms-1 at angle 𝜃 to line AB.
The fragment of mass 1.5M has a velocity of 8.0ms-1 at angle 𝜃 to line AB.
(i)
Use the principle of conservation of momentum to determine 𝜃.
𝜃 = ........................................................ ° [3]
(ii)
Calculate the ratio
kinetic energy of fragment of mass 2.0 𝑴
kinetic energy of fragment of mass 1.5 𝑴
ratio = ...........................................................[2]
[Total: 7]
3. A child on a sledge slides down a steep hill and then travels in a straight line up an ice-covered
slope, as illustrated in Fig. 3.1.
The sledge passes point A with speed 18ms–1 at time t = 0 and then comes to rest at point B.
The child applies a brake to the sledge at point B. The brake does not keep the sledge stationary
and it immediately slides back down the slope towards A.
The variation with time t of the velocity v of the sledge from t = 0 to t = 24 s is shown in Fig.
3.2.
(a) State the time taken for the sledge to travel from A to B.
time = ........................................................s [1]
(b) Determine the displacement of the sledge up the slope from point A at time t = 24 s.
displacement = .......................................................m [3]
(c) Show that the acceleration of the sledge as it moves from B back towards A is 0.50 ms-2.
[2]
(d) The child and sledge have a total mass of 70 kg. The component of the total weight of the
child and sledge that acts down the slope is 80 N.
Determine
(i)
the frictional force on the sledge as it moves from B towards A,
frictional force = ....................................................... N [2]
(ii)
the angle 𝜃 of the slope to the horizontal.
𝜃 = ........................................................ ° [2]
(e) The child on the sledge blows a whistle between t = 4.0 s and t = 8.0 s. The whistle emits
sound of frequency 900Hz. The speed of the sound in the air is 340 ms-1. A man standing
at point A hears the sound.
Use Fig. 3.2 to
(i)
determine the initial frequency of the sound heard by the man,
initial frequency = ..................................................... Hz [2]
(ii)
describe and explain qualitatively the variation, if any, in the frequency of the
sound heard by the man.
...................................................................................................................................
..............................................................................................................................[1]
[Total: 13]
4. (a) State what is meant by work done.
.......................................................................................................................................................
..................................................................................................................................................[1]
(b) A diver releases a solid sphere of radius 16 cm from the sea bed. The sphere moves vertically
upwards towards the surface of the sea.
The weight of the sphere is 20 N. The upthrust acting on the sphere is 170 N. The upthrust
remains constant as the sphere moves upwards.
(i)
Calculate the density of the material of the sphere.
density = ............................................... kgm-3 [2]
ii)
Briefly explain the origin of the upthrust acting on the sphere.
.........................................................................................................................................
.........................................................................................................................................
.....................................................................................................................................[1]
iii)
Calculate the acceleration of the sphere as it is released from rest.
acceleration = ................................................. ms-2 [2]
[Total: 6]