Unit I: Scientific Thinking in Experimental Settings

SCIENCE DEPARTMENT
IGCSE PHYSICS MOMENTUM REVISION WORKSHEET
NAME:__________________________________
1. (a) Define momentum.
(b) Explain whether or not momentum is a vector.
2. What is the momentum of
a. A car of mass 800kg moving east at a speed of 25m/s.
b. A bullet of mass 50g traveling at 450m/s.
3.
A ball of mass 200g has a total momentum of 8kgms-1. What is its velocity?
4. A car of mass 800kg travelling at 10m/s is uniformly accelerated to 25m/s. Calculate its
a. Total momentum before acceleration.
b. Total momentum after acceleration.
c. The change in momentum during acceleration.
5. A ball of mass 200g travelling at 10m/s bounces off a wall. If after hitting the wall it travels at 5m/s find
a. Momentum before hitting the wall.
b. Momentum after hitting the wall.
c. The change in momentum.
1
6.
The momentum P is given by P=mV. Explain why P and V are in bold.
7. Ball A has a mass of 50g and is travelling at 28m/s east. It collides with ball B of mass 100g travelling at 12m/s
in the same direction. After collision, ball A moves at 10m/s east and ball B moves at 21m/s in the same
direction. Calculate
a. The total momentum before collision
b. Total momentum after collision
c. Comment on your results
8. Calculate the magnitude of the momentum of a car of mass 0 .5 tonnes travelling at 22m/s.
9. State the principle of conservation of momentum.
10. A car of mass 800kg travelling at 20m/s to the right collides with a truck of mass 1200kg at rest. If the truck
moves in the same direction at 4m/s, find
(a) Total momentum before collision
(b) the speed and direction of the car after collision.
11. Kim holds a 2.0 kg air rifle loosely and fires a bullet of mass 1.0 g. The velocity of the bullet is 150 m/s.
What is the recoil speed of the rifle? Recoil speed is the speed at which the rifle moves back.
[Hint : momentum before firing =0].
2
12. Railway truck A of mass 800kg is moving along a horizontal track at 5ms-1.It collides with a stationary
truck B of mass 1200kg and on collision the two join together and move at a speed v. Calculate
a. The speed v after collision
b. The total energy lost during the collision.
c. Suggest what happens to the lost energy.
13. (a) What is Impulse?
(b) State the units of impulse.
14. Calculate the impulse when
a. A man is pulling a roller east with a constant force of 500N for 12s.
b. Hammer weighing 20N hits a nail with a vertical force of 800N for 50ms.
15. While being thrown, a net force of 1320 N acts on a baseball for a period of 4.5 x 10-2 sec. What is the
magnitude of the change in momentum of the ball?
16. A tennis ball of mass 60g is moving horizontally with speed of 20m/s. A player hits the back so that it
leaves his racket with a speed of 25m/s. What is the
a. Size of the change in momentum of the ball.
b. The impulse of the force which the racket exerts on the ball.
3
17.
18.
19.
20.
21.
22.
A 1,200-kilogram car traveling at 10. meters per second hits a tree and is brought to rest in 0.10 second.
What is the magnitude of the average force acting on the car to bring it to rest?
A.
B.
C.
D.
1.2 × 102N
1.2 × 103N
1.2 × 104N
1.2 × 105N
4
23.
24.
25.
Which one of the following statements is correct?
The force acting on an object is equivalent to:
A
its change of momentum.
B
the impulse it receives per second.
C
the energy it gains per second.
its acceleration per metre.
D
A shell explodes and many pieces fly off in different directions. The following is conserved
A.
Kinetic energy
C.
Both
B.
Momentum
D.
None of these.
A bullet weighing 50 gm leaves the gun with a velocity of 30 ms–1. If the recoil speed imparted to the gun is
1ms–1, the mass of the gun
26.
A.
1.5 kg
C.
20 kg
B.
15 kg
D.
30 kg
Which of the following statements are true about momentum?
A. Momentum is a vector quantity.
B. The standard unit on momentum is the Joule.
C. An object with mass will have momentum.
D. An object which is moving at a constant speed has momentum.
27.
28.
If the momentum of a ball is doubled, then the kinetic energy is
A. 0.5 times larger.
C. 3 times larger.
B. 2 times larger.
D. 4 times larger.
A 4.00 kg ball is traveling at 5.00 m/s and strikes a wall. The 4.00 kg ball bounces off the wall with a
velocity of 4.0 m/s. The change in momentum of the ball is
29.
A. 4.0 kg m/s.
C. 36 kg m/s.
B. 13 kg m/s.
D. 30 kg m/s.
A machine gun fires 60.0 gram bullets at 6 bullets a second. If the velocity of the bullets is 600 m/s, then
the average force on the machine gun is
A. 75.0 N.
B. 94.0 N.
C. 109 N.
D. 216 N.
5