Question

A man can throw a stone 80 m. The maximum height to which he can raise the stone is

• A. 10 m
• B. 15 m
• C. 30 m
• D. 40 m

Answer 1

The correct option is D 40 m

$R_{max}=\frac{u^2}{g}=80m[for\theta ={45}^{\circ }]$
But height can be maximum when body projected vertically up
$H_{max}=\frac{u^{2}si{n}^2{90}^{\circ }}{2g}=\frac{u^2}{2g}=\frac{1}{2}\left(\frac{u^2}{g}\right)=40m$