Question

From the top of a $64$ metres high tower, a stone is thrown upwards vertically with a velocity of $48\text{m/s}$. The greatest height (in metres) attained by the stone, assuming the value of gravitational acceleration $g=32{\text{m/s}}^2$, is

(Note: This question was asked in Maths subject in JEE Mains $2015$ online exam held on $11$ April $2015$)

• A. 100
• B. 88
• C. 128
• D. 112

Answer 1

The correct option is A 100

$u=48\text{m/s},a=-32{\text{m/s}}^2$

At the highest point, $v=0$

Since, $v^2-u^2=2as$,

$\Rightarrow |s|=\left|\frac{0^2-{48}^2}{2\times 32}\right|$ m

$\Rightarrow |s|=36m$

So, total height attained by the stone from the ground $=$ $36+64=100$ m