A man can swim in still water with a speed of `2 ms^-1`. If he wants to cross a river of water current speed `sqrt(3) ms^-1` along the shortest possible path, then in which direction should he swim ?

Options

A. At an angle `120^@` to the water current.
B. At an angle `150^@` to the water current.
C. At an angle `90^@` to the water current.
D. None of these

Answer

B

Explanation

`sin alpha =u/v =sqrt3/2`
`rArr alpha=60^@`
`rArr theta =90^@ +alpha = 150^@`