Question

A tennis player hits a 1.45 kg tennis ball with a racket of mass 2.5 kg. If he hits the ball with a velocity of 7.5 m/s and then stops, what impulse did he imply on the ball? What is the ball’s velocity?

Answer 1

I = mΔv
I = 2.5 x (7.5 - 0) = 18.75 kg.m/s

Now, considering that the ball´s initial velocity was zero, we have:

1.45 x 0 + 2.5 x 7.5 = 1.45 x V
1.45V = 18.75
V = 12.93 m/s