Swimmer’s velocity in a river: physics problem

Practice question

Question

A swimmer moves north at 3m/s in a river flowing west at 4m/s. What is the magnitude of the swimmer’s velocity relative to the ground?

Options

Choose one · Correct answer highlighted

3 m/s 5 m/s Correct 7 m/s 4 m/s

Explanation

Velocity components: vx=−4m/s,vy=3m/s. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 5 m/s as the result, so option B is correct.

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