Question

A boy can swim in still water at 1 m/s. He swims across a river flowing at 0.6 m/s which is 336 m wide. If he travels in shortest possible time, then the resultant velocity of swimming must be:

• A. perpendicular to river flow
• B. in a direction making obtuse angle with river flow
• C. in a direction making acute angle with river flow
• D. cant be determined.

Answer 1

The correct option is C in a direction making acute angle with river flow

For shortest time he has to make perpendicular strokes.

$\therefore$ Resultant will be acute angle

Hence,

option $C$ is correct answer.