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

(b) `sin prop = (u)/(v) = (sqrt(3))/(2) rArr prop = 60^@`
`rArr theta = 90^@ + prop = 150^@`.
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