Question

A man standing on the ground sees that rain is falling from a northwest direction. In what direction should he run, so that rain may fall on him vertically?

• A. In the west direction
• B. In the east direction
• C. In the north direction
• D. In the south direction

Answer 1

The correct option is B In the east direction

From the figure,
Velocity of rain, ${\overrightarrow{v}}_r=x\hat{i}-y\hat{j}$
If velocity of man, ${\overrightarrow{v}}_m=x\hat{i}$
velocity of rain w.r.t man, ${\overrightarrow{v}}_{rm}={\overrightarrow{v}}_r-{\overrightarrow{v}}_m=-y\hat{i}$
Hence we can say that if the man starts running in the east direction at an appropriate speed, the rain may fall on him vertically.

Hence the correct option is (b).