Answer:
The velocity of the ball relative the racquet is 15 m/s.
Explanation:
Given;
velocity of the tennis ball,
= 30 m/s
Velocity of the racquet swung in opposite direction,
= 15 m/s
The velocity of the ball relative the racquet (
) is calculated as;

Therefore, the velocity of the ball relative the racquet is 15 m/s.