In the elastic collision between two billiard balls. The variation of potential energy is represented by the graph (here r is the distance between centres of the balls and R is radius of the ball)

In the elastic collision between two billiard balls. The variation of

1.	In the elastic collision between two billiard balls. The variation of potential energy is represented by the graph (here r is the distance between centres of the balls and R is radius of the ball)
Answer» ANSWER :D