Question

A ball rolls off top of a staircase with a horizontal velocity u m/s. If the steps are h metre high and b metre wide, the ball will just hit the edge of nth step if n equals to

• A.
• B.
• C.
• D.

Answer 1

The correct option is C


By using equation of trajectory $y=\frac{g{x}^2}{2u^2}$ for given condition
$nh=\frac{g(nb{)}^2}{2u^2}\therefore n=\frac{2h{u}^2}{g{b}^2}$