A rubber ball is dropped from a height of `5m `on a plane, where the acceleration due to gravity is not shown. On bouncing it rises to `1.8 m.` The ball loses its velocity on bouncing by a factor of

Options

A. `16//25`
B. `2//5`
C. `3//5`
D. `9//25`

Answer

C

Explanation

Since, height after `n^(th)` collision-
`h_n =e^(2n)h_0`
`impliesh_1=e^2 h_0`
`implies e=sqrt(h/h_0)=sqrt((1.8)/5)=sqrt(9/25)=3/5`