Question

A person throws a ball with speed $10m/s$ at an angle of $30^{\circ }$ with horizontal from the top of $10m$ high tower. The distance of ball from the foot of the tower after falling on the ground will be

• A. $7m$
• B. $8.6m$
• C. $9.6m$
• D. $10m$

Answer 1

Answer: (B)

The ball will be at a point $P$ when it is at a height of $10m$ from the ground. So, we have to find the distance $OP$, which can be calculated directly by considering it as a projectile on a levelled plane $OX$.
Therefore, maximum range, $OP=R=\frac{u^2\sin 2\theta }{g}$
$=\frac{10^2\times \sin \left(2\times 30^{\circ }\right)}{10}=\frac{10\sqrt{3}}{2}=5\sqrt{3}=86m$