Question

A tennis player receives a shot with the ball (0.060 0 kg) traveling horizontally at 56.0 m/s and returns the shot with the ball traveling horizontally at 34.5 m/s in the opposite direction. (Assume the initial direction of the ball is in the −x direction.)

(a) What is the impulse delivered to the ball by the racquet?
(b) What work does the racquet do on the ball?How many Joules?

Answer 1

Step-by-step explanation:

It is given that,

Mass of the ball, m = 0.06 kg

Initial speed of the ball, u = 56 m/s

Final speed of the ball, v = -34.5 m/s (opposite direction)

(a) Let J is the impulse delivered to the ball by the racquet. It is equal to the change in momentum of the object as :

`J=m(v-u)`

`J=0.06\ kg(-34.5\ m/s-56\ m/s)`

J = -5.43 kg-m/s

(b) The work done by the racquet on thee ball is equal to the change in kinetic energy as :

`W=(1)/(2)m(v^2-u^2)`

`W=(1)/(2)* 0.06((-34.5)^2-(56)^2)`

W = -58.372 Joules