Question

A person aiming to reach the exactly opposite point on the bank of stream is swimming with a speed of 0.5 m/s at an angle of ${120}^{\circ }$ with the direction of flow of water. The speed of water in the stream is

• A. 1 m/s
• B. 0.5 m/s
• C. 0.25 m/s
• D. 0.433 m/s

Answer 1

The correct option is C 0.25 m/s

The component of velocity of man in $opposite$ direction of the flow is $0.5\times Cos({180}^0-{120}^0)=0.25m/s$

so the velocity of flow(stream) will also be $0.25m/s$

so that the person can oppose the stream and in result he will not be $drifted$ by the stream and will reach directly

opposite side.