Question

A boy running on a circular track of radius $10\text{m}$ completes $3$ revolution and comes back to the point from where he started. Calculate the angular displacement of the boy $\left(\text{in rad}\right)$.

• A. $3\pi$
• B. $6\pi$
• C. $0$
• D. $\frac{\pi }{3}$

Answer 1

The correct option is B $6\pi$

We know that, to complete one cycle the angular displacement is $2\pi$ and for $3$ revolution the angular displacement will be, $3\times 2\pi =6\pi$

Hence the correct option is (b).