WorksheetsForce and laws of motion class 9
Total questions: 15
Worksheet time: 9mins
The inertia of a moving object depends on
Mass of the object
Momentum of the object
Speed of the object
Shape of the object
A man wearing a bullet-proof vest stands on roller skates. The total mass is 80 kg. A bullet of mass 20 g is fired at 400 m/s. It is stopped by the vest and falls to the ground. What is then the velocity of the man?
1 m/s
0.1 m/s
0.01 m/s
0 m/s
The speed of a car weighing 1500 kg increases from 36 km/h to 72 km/h uniformly. What will be the change in momentum of the car?
15000 kg km/h
15000 kg m/s
54000 kg m/s
54000 g m/s
A body of mass 25 kg has a momentum of 125 kg.m/s. Calculate the velocity of the body.
(a)
What name is given to the product of mass and velocity of a body?
(a)
What is the total momentum of the bullet and the gun before firing?
0
2
1
Which principle is followed in a take off of a rocket?
Moment of inertia
Conservation of momentum
Newton’s third law of motion
Newton’s law of gravitation
An object of mass 2 kg is sliding with a constant velocity of 4 m/s on a friction less horizontal table. The force required to keep the object moving with the same velocity is
32 N
0 N
2 N
8 N
A goalkeeper in a game of football pulls his hands backwards after holding the ball shot at the goal. This enables the goalkeeper to
Exert large force on the ball
Increases the force exerted by the ball on hands
Increase the rate of change of momentum
Decrease the rate of change of momentum
If a net force of 5 N was constantly applied on 200 g object at rest, how long will it take to raise its velocity to 150 m/s?
2 sec
6 sec
4 sec
8 sec
