Question

A stone is thrown vertically at a speed of $30m{s}^{-1}$ making an angle of ${45}^o$ with the horizontal. What is the maximum height reached by the stone ? Take $g=10m{s}^{-2}$.

• A. 30 m
• B. 22.5 m
• C. 15 m
• D. 10 m

Answer 1

Answer: (B)

22.5 m

Given : $u=30$ $m/s$ $\theta ={45}^o$

Maximum height reached $H=\frac{u^2{\sin }^2\theta }{2g}$ $({\sin }^2{45}^o=0.5)$

$\therefore$ $H=\frac{{30}^2\times 0.5}{2\times 10}=22.5$ m