Question

A stone is projected from the ground with velocity 25 m/s. Two seconds later, it just clears a wall 5 m high. The angle of projection of the stone is $(g=10m/se{c}^2)$

• A. ${30}^{\circ }$
• B. ${45}^{\circ }$
• C. ${50.2}^{\circ }$
• D. ${60}^{\circ }$

Answer 1

The correct option is A

${30}^{\circ }$

For vertical upward motion $h=ut-\frac{1}{2}g{t}^2$
$5=\left(25sin\theta \right)\times 2-\frac{1}{2}\times 10\times (2{)}^2$
$\Rightarrow 25=50sin\theta \Rightarrow sin\theta =\frac{1}{2}\Rightarrow \theta ={30}^{\circ }$