Question

Question 2
A body is thrown vertically upward with velocity u, the greatest height h to which it will rise is,
(a) $\frac{u}{2}$
(b) $\frac{u^2}{2g}$
(c) $\frac{u^2}{g}$
(d) $\frac{u}{2g}$

Answer 1

Let initial velocity be $u$, final velocity be $v$, acceleration due to gravity be $g$ and distance covered be $h$.
Given, final velocity, $v=0$
Using Newton’s third equation of motion,
$v^2=u^2-2gh$ ('g' is negative because the body is thrown up, i.e it's motion is against gravity)
$\Rightarrow 2gh=u^2$
$\Rightarrow h=\frac{u^2}{2g}$