Question

A bomb is dropped on an empty post by an aeroplane flying horizontally with a velocity of $60km{h}^{-1}$ and at a height of $490m$. At the time of dropping the bomb, how far the aeroplane should be from the empty post so that the bomb may directly hit the target? (Take $g=9.8m/s^2$)

• A. $\frac{400}{3}m$
• B. $\frac{500}{3}m$
• C. $\frac{1700}{3}m$
• D. $498m$

Answer 1

Answer: (B)

$\frac{500}{3}m$

Time taken for vertical direction motion
$t=\sqrt{\frac{2h}{g}}=\sqrt{\frac{2\times 490}{9.8}}=\sqrt{100}=10s$

The same time is for horizontal direction .
$\therefore x=vt=(60\times \frac{5}{18})\times 10=\frac{500}{3}m$