A ball rolls off top of a staircase with a horizontal velocity `u m s^-1`. If the steps are `h` metre high and `b` mere wide, the ball will just hit the edge of `n th` step. Find the value of `n`.

Options

A. `n=(gx^(@))/(2hu^(2))`
B. `n=(2hu^(2))/(gw^(2))`
C. `n=(2u^(2))/(gw^(2)h)`
D. `n=(2hw^(2)u^(2))/(g)`

Answer

b

Explanation

nw=ut (for horizontal motion)
`nh=(1)/(2)g t^(2)` (for vertical motion)
`nh=(1)/(2)g((nw)/(u))^(2)`
`nh=(1)/(2)(gn^(2)w^(2))/(u^(2))`
`n=(2hu^(2))/(gw^(2))`