how would you solve this problem

Question

A tennis player returns a 30 m/s serve straight back ( opposite direction) at -25 m/s after making contact with the ball for .05 sec. If the ball has a mass of .20kg, determine the amount of force the player exerted.

Answer 1

Force of impact = mass x acceleration

 

acceleration = change in speed/time = (final velocity - initial velocity)/ time

 

                                                     = (-25m/s  - 30 m/s) / (0.05 s)

 

                                                      = -55 m/s  divided by 0.05 s

 

                                                       = -1100 meters per second squared.

 

Force F = .20 kg x -1100 meters per second squared

 

           = 220 Newtons of force