Two balls of equal mass are thrown with equal velocities against a massive wall. The first rebounds with a speed equal to its striking speed, and the second sticks to the wall. The impulse that the first ball transmits to the wall, relative to the second, is
A) twice as great.
B) half as great.
C) the same.
D) four times as great.
E) one-fourth as great.

Question

Quizplus · Accepted Answer

The impulse is the change in momentum. For the first ball, the change in momentum is twice its initial momentum because it rebounds with the same speed. For the second ball, the change in momentum is equal to its initial momentum because it sticks to the wall. Therefore, the impulse transmitted by the first ball is twice as great as that of the second.

Two Balls of Equal Mass Are Thrown with Equal Velocities