Question

A swimmer wants to cross a river from point A to point B. Line AB makes an angle of 30° with the flow of river. Magnitude of velocity of the swimmer is same as that of the river. The angle θ with the line AB should be ______°, so that the swimmer reaches point B. 

Options

• 10

• 20

• 30

• 40

Answer 1

A swimmer wants to cross a river from point A to point B. Line AB makes an angle of 30° with the flow of river. Magnitude of velocity of the swimmer is same as that of the river. The angle θ with the line AB should be 30°, so that the swimmer reaches point B. 

Explanation:

The magnitude of the swimmer's velocity, according to the question, is the same as that of the river.

As a result, the resultant would pass exactly halfway through them.

∴ Angle θ = 30°