Question

A player throws a ball vertically upwards. The ball attains a height of $25m$ and returns back. Find the initial speed of the ball.

Answer 1

Let the initial velocity of the particle be $u$.

Then , maximum height = $\frac{u^2}{2g}$

Now , $\frac{u^2}{2g}$ = $25$

Taking g = $10m{s}^{-2}$

$u^2=500$

$u=10\sqrt{5}m{s}^{-1}$.