Question

A ball is hit by a batsman at an angle of ${37}^{\circ }$ as shown in the figure. With what minimum velocity should the man standing at $P$ run so that he catches the ball before it strikes the ground. Assume that height of a man is negligible in comparison to the maximum height of projectile. $(g=10m/s^2)$

• A. $3m{s}^{-1}$
• B. $5m{s}^{-1}$
• C. $9m{s}^{-1}$
• D. $12m{s}^{-1}$

Answer 1

The correct option is B $5m{s}^{-1}$

Time of flight is given as, $T=\frac{2u\sin \theta }{g}$
And time taken by man $=\frac{9}{v_m}$
Man’s travelling time must be the same as Time of flight to catches the ball.
$\Rightarrow \frac{9}{v_m}=\frac{2u\sin \theta }{g}{v}_m=\frac{9g}{2u\sin \theta }{v}_m=\frac{9\times 10}{2\times 15\times \sin {37}^{\circ }}{v}_m=5m/s$