Question

A river is flowing from east to west at a speed of $5m/min$. A man on south bank of river, capable of swimming $10m/min$ in still water, wants to swim across the river in shortest time. He should swim,

• A. Due north-east with double the speed of river
• B. Due north-east
• C. Due north
• D. none of these

Answer 1

The correct option is C Due north

Step 1:
Draw a labelled diagram.

Step 2:
Find the direction of swimmer.
For shortest time, swimmer should swim along 𝐴𝐵, so he will reach at point 𝐶 due to the velocity of river. i.e., he should swim due north.
Final Answer: (a)