Question

A body is projected vertically upwards with velocity $um{s}^{-1}$. When it returns to the point of projection, its velocity is

• A. $u$ $m{s}^{-1}$
• B. $0$ $m{s}^{-1}$
• C. $-u$ $m{s}^{-1}$
• D. $\sqrt{u}$ $m{s}^{-1}$

Answer 1

Answer: (C)

$-u$ $m{s}^{-1}$

The value of the velocity in its downward motion will be same. But it will have opposite direction. So in the upward journey if the velocity = u, in the downward journey in the same point the velocity will be (-u).

$v^2=u^2+2as$
$s=0⟹v=\pm u$

where + is for projection and - is for return.