Question

A car is travelling at a velocity of $10$kmph on a straight road. The driver of car throws a parcel with a velocity of $10\sqrt{2}$kmph when car is passing by a man standing on the side of a road. If parcel just reaches the man, the direction of throw makes following angle with the direction of car

• A. ${135}^{\circ }$
• B. ${45}^{\circ }$
• C. ${\tan }^{-1}\left(\sqrt{2}\right)$
• D. $\tan (1/\sqrt{2})$

Answer 1

The correct option is A ${135}^{\circ }$

When the car is opposite, the man at least distance, the parcel will reach him when thrown with velocity $v_p$.
now, $\sin \theta =d\frac{v_p}{v_c}=\frac{10}{10\sqrt{2}}=1/2$
$\Rightarrow \theta ={45}^o$
Thus, total angle between car and parcel $=90+\theta =90+45={135}^o$