A tennis player receives a ball on his racket. The ball has a mass m = 57 g and it is approaching the racket at a speed v1 of 60 km/h. Suppose the player hits the ball back with a speed of v2 = 70 km/h. Assume that when the racket hits the ball, it is momentarily at rest, so assume that the speed of the racket is zero. Also, assume that the collision is elastic (No loss of energy).
a. Suppose that the contact last delta t -= 10-3 s. Compute the average force.
b. Compute the work done by force applied by the racket on the ball.