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 $H/2$ in $T/2$ sec
• B. It acquires velocity $u/2$ in $T/2\sec$
• C. Its velocity is $u/2$ at $H/2$
• D. Same velocity at $2T$

Answer 1

Answer: (B)

It acquires velocity $u/2$ in $T/2\sec$

Answer 2

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 $\frac{u}{2}$