Question

A plane flying horizontally at $100m{s}^{-1}$ releases an object which reaches the ground in $10s$. At what angle with horizontal it hits the ground?

• A. ${55}^{\circ }$
• B. ${45}^{\circ }$
• C. ${60}^{\circ }$
• D. ${75}^{\circ }$

Answer 1

The correct option is B ${45}^{\circ }$

We know $V=U+at$

for object ${\mu }_y-$ direction $=0$

$\Rightarrow$ Velocity on reaching ground $V=gt=100$ m/s

(given $t=10$)

${\mu }_x$ of object $=$ Velocity of plane $=100$ m/s

$\tan \theta =\frac{100}{100}=1\Rightarrow \theta ={45}^0$