Two persons standing on a frictionless surface throw a ball back and forth. Which statement (s) is true?

Options

A. The interaction mediated by the ball is repulsive.
B. If we film the action and play the movie backward, the interaction appears attractive.
C. The total momentum of the two person and ball is conserved.
D. The total mechanical energy of the two people is conserved.

Answer

A, C

Explanation

(A) Separation between them increases with increasing.
(B) `F=(dp)/(dt)=(-ve)/(-ve)=+ve`
(C) `SigmaF_(system)^(ext)=0`
(D) Internal energy is consumed