Question

A 0.060 kg ball hits the ground with a speed of -32m/s. The ball is in contact with the ground for 45 milliseconds and the ground exerts a +55 N force on the ball. What is the magnitude of the velocity after it hits the ground?

A. 9.3m/s
B.12m/s
C.41m/s
D.73m/s

Answer 1

it's A. i took the test right now

Answer 2

Using the kinematic equation V=Vo + at, the initial velocity (Vo) is -32, the acceleration (a) is found by dividing force by mass 55N/.06kg=916.66 m/s/s, and the time is 0.045 sec.

V=Vo+at
V=-32+916.66*.045
V=9.25

The answer is A.