In the previous problem , time taken by the ball up to the third collision

Options

A. `3 s`
B. `4 s`
C. `5 s`
D. `6 s`

Answer

A

Explanation

Time from O to A :` t_(0) = sqrt((2h)/(g)) = 2s`
Time from A to B , `t_(1) = e t_(0) = 1 s`
Time from A to C : `t_(2) = e^(2) t_(0) = 0.5 s`
Time from `O` to the third collision
`T = t_(0) + 2t_(1) + 2 t_(2) = 5 s`