Question

A body is projected up with a speed 'u' and the time taken by it is T to reach the maximum height H . Pick out the correct statement

• A. It reaches $\frac{H}{2}$ in $\frac{T}{2}$ sec
• B. It acquires velocity $\frac{U}{2}$ in $\frac{T}{2}$ sec
• C. Its velocity is $\frac{U}{2}$ at $\frac{H}{2}$ sec
• D. Same velocity at 2T

Answer 1

The correct option is B It acquires velocity $\frac{U}{2}$ in $\frac{T}{2}$ sec

At maximum height velocity v=0.
We know that v-u+at,hence
0=u-gT$\Rightarrow$u=gT
When$v=\frac{u}{2},$then
$\frac{u}{2}=u-gt\Rightarrow gt=\frac{u}{2}\Rightarrow gt=\frac{gT}{2}\Rightarrow t=\frac{T}{2}$
hence,at$t=\frac{T}{2}$,it acquires velocity $\frac{u}{2}$