A man running at a speed of 5 kmph finds that the rain falls vertically. When he stops running, he finds that the rain is falling at an angle of 60° with the horizontal. The velocity of rain with respect to running man is

Options

A. `(5)/(sqrt(3))km//h`
B. `(5sqrt3)/(2)km//h`
C. `(4sqrt3)/(2)km//h`
D. `5sqrt(3)km//h`

Answer

D

Explanation

Consider the situational diagram as shown below.

In `DeltaOAP, tan30^(@)=(v_(m))/(v_(rm))=("Velocity of man")/("Velocity of rain with respect to man")`
`Rightarrow v_(rm)=(5)/(1//sqrt3)=5sqrt(3)km//h`