Question

A ball is dropped from a height h. If the coefficient of restitution be e, then to what height will it rise after jumping twice from the ground?

• A. e h/2
• B. 2 e h
• C. e h
• D. $e^{4}h$

Answer 1

The correct option is D $e^{4}h$

Height upto which the ball rebound after nth collision , $H_n=e^{2n}{H}_{initial}$

Given : Coefficient of restitution be $e$ $H_{initial}=h$

Let the height upto which the ball rebound after two collisions be $H_2$

$\therefore$ $H_2=e^{2\times 2}\times h=e^{4}h$