A 2.0 kg softball is pitched to you at 20. m/s. You hit the ball back along the same path, and at the same speed. If the bat was in contact with the ball for 0.10 s, the average force the bat exerted was
A) 0.40 kN.
B) zero.
C) 40. N.
D) 0.65 kN.
E) 0.80 kN.

Question

Quizplus · Accepted Answer

The change in momentum is 2 * 2.0 kg * 20 m/s = 80 kg*m/s. The average force is the change in momentum divided by the contact time: 80 kg*m/s / 0.10 s = 800 N or 0.80 kN.

A 20 Kg Softball Is Pitched to You at 20