Physics Practice Tests – Newton’s Law of Motion

A catapult used to hold a stone of mass 500 g is extended by 20 cm with an applied force F. If the stone leaves with a velocity of 40 ms^-1, the value of F is _______

A. 4.0 x 10⁴ N    B. 4.0 x 10³ N    C. 2.0 x 10³ N    D. 4.0 x 10² N

A man stands on a spring scale placed in a lift. The lift descends at constant velocity. As a result, the scale reads a weight _______ (JAMB 1982) 

A. greater than the weight of the man
B. the same as the weight of the man
C. of zero
D. less than the weight of the man

When taking a penalty kick, a footballer applies a force of 30.0 N for a period of 0.05 s. If the mass of the ball is 0.075 kg, calculate the speed with which the ball moves off. (JAMB 1989) 

A. 4.50 ms^-1       B. 11.25 ms^-1       C. 20.0 ms^-1       D. 45.00 ms^-1

The driver in a motor car, of which the total mass is 800 kg and which is travelling at 20 ms^-1, suddenly observes a stationary dog in his path 50 m ahead. If the car brakes can exert a force of 2000 N, what will most likely happen? (JAMB 1981) 

A. The car will be able to stop immediately the driver notices the dog
B. The car will stop 30 m after hitting the dog
C. The car will stop 20 m in front of the dog
D. The driver will quickly reverse the car

A force of 100 N is used to kick a football of mass 0.8kg. Find the velocity with which the ball moves if it takes 0.8s to be kicked. (JAMB 2003) 

A. 32 ms^-1       B. 50 ms^-1      C. 64 ms^-1       D. 100 ms^-1