A 0.140-kg baseball is dropped and reaches a speed of 1.20 m/s just before it hits the ground. It rebounds with a speed of 1.00 m/s. What is the change of the ball's momentum?
A) 0.0280 kg∙m/s upwards
B) 0.0280 kg∙m/s downwards
C) 0.308 kg∙m/s upwards
D) 0.308 kg∙m/s downwards
E) 0 kg∙m/s

Question

Quizplus · Accepted Answer

The change in momentum is equal to the final momentum minus the initial momentum.

Initial momentum = 0, since the ball is initially at rest.

Final momentum = (mass of the ball) x (final velocity)

Final momentum = (0.14 kg) x (1.00 m/s)

Final momentum = 0.14 kg∙m/s

Therefore, the change in momentum is:

Change in momentum = Final momentum - Initial momentum

Change in momentum = 0.14 kg∙m/s - 0

Change in momentum = 0.14 kg∙m/s

Since the ball rebounds with a speed of 1.00 m/s, the change in momentum is in the upward direction (opposite to the direction of gravity), so the correct answer is C) 0.308 kg∙m/s upwards.

A 0140-Kg Baseball Is Dropped and Reaches a Speed of 1