The stream of a river is flowing with a speed of 2 km/h. A swimmer can swim at a speed of 4 km/h. What should be the direction of the swimmer with respect to the flow of the river to cross the river straight?

Options

A. `90^(@)`
B. `150^(@)`
C. `120^(@)`
D. `60^(@)`

Answer

c

Explanation

To cross the river straight
`V_(s)sintheta= V_(r) :. Sintheta= (v_(r))/(v_(s))= (2)/(4)= (1)/(2)`
`:. Theta= 30^(@)`
Direction of swimmer with respect to flow.
`= 90^(@)+ 30 ^(@)= 120^(@)`