Question

A man running at a speed of $5kmph$ find that the rain falls vertically. When he stops running , he finds that the rain is falling at an angle of ${60}^{\circ }$ with the horizontal.The velocity of rain with respect to running man is :

• A. $\frac{5}{\sqrt{3}}kmph$
• B. $\frac{5\sqrt{3}}{2}kmph$
• C. $\frac{4\sqrt{3}}{5}kmph$
• D. $5\sqrt{3}kmph$

Answer 1

The correct option is D $5\sqrt{3}kmph$

$tan{30}^{\circ }=\frac{V_m}{V_{r}m}$

$V_{r}m=\frac{5}{\frac{1}{\sqrt{3}}}=5\sqrt{3}kmph$