Step-by-step explanation:
It is given that,
Mass of the tennis ball,

Initial speed of tennis ball,

Mass of ball,

Initial speed of ball,

In case of elastic collision, the momentum remains conserved. The momentum equation is given by :

are final speed of tennis ball and the ball respectively.

..............(1)
We know that the coefficient of restitution is equal to 1. It is given by :


.................(2)
On solving equation (1) and (2) to find the values of velocities after collision.


So, the speed of both balls are 5.28 m/s and 3 m/s respectively. Hence, this is the required solution.