A person is standing on road by holding an umbrella at right angle to the horizontal surface in order to protect himself from rain falling at a speed of 10 m/s, when the velocity of wind is zero. Suddenly wind begins to flow at a speed of 20m/s, `30^(@)` south of west. Now by what angle the person has to rotate his umbrella in order to protect himself from rain ?

Options

A. `30^(@)`
B. `tan^(-1) (2)`
C. `60^(@)`
D. `tan^(-1) ((sqrt3)/(2))`

Answer

B

Explanation

`tan theta = (20)/(10)`