Question

A man can swim in still water with a speed of 2 m/s. If he wants to cross a river of water current speed $\sqrt{3}$ m/s along shortest possible path, then in which direction should he swim?

• A. at an angle $120^{\circ}$ to the water current
• B. at an angle $150^{\circ}$ to the water current
• C. at an angle $90^{\circ}$ to the water current
• D. none of these

Answer 1

Answer: (B)

sin $\theta=\frac{\sqrt{3}}{2}\Rightarrow \theta=60^{\circ}$

Hence $150^{\circ}$ with water current.