A rubber ball and a lump of putty have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The putty sticks to the wall. Which objects experiences the greater momentum change?
A) the ball
B) the putty
C) Both experience the same non-zero momentum change.
D) Both experience zero momentum change.
E) Cannot be determined from the information given.

Question

Quizplus · Accepted Answer

The momentum change of an object is given by the expression:
Δp = mΔv
where Δp is the momentum change, m is the mass of the object, and Δv is the change in velocity.
Since both the ball and the putty have the same mass and are thrown with the same initial velocity, the only difference in their momentum change will be due to the change in velocity upon hitting the wall.
The ball bounces back with nearly the same speed, so its change in velocity is large in magnitude but in the opposite direction. This means that the ball experiences a large momentum change.
The putty, on the other hand, sticks to the wall and thus experiences zero change in velocity. Therefore, the putty experiences zero momentum change. 
Thus, the ball experiences the greater momentum change.

A Rubber Ball and a Lump of Putty Have Equal