Answer:
due to production of heat through friction
See if you get the answer with this formulae.
B - A theory seems to be the closest
Answer:Racquet force is twice of Player force
Explanation:
Given
ball arrives at a speed of 
ball returned with speed of 
average Force imparted by racquet on the ball is given by

where 
time of contact of ball with racquet


When it land on the player hand its final velocity becomes zero and time of contact is same as of racquet


From 1 and 2 we get

Hence the magnitude of Force by racquet is twice the Force by player
Answer:
Explanation:
The quantity of energy transferred by a force when it is applied to a body and causes that body to move in the direction of the force work.