Question

A car runs at a constant speed on a circular track of radius $200\text{m}$, taking $62.8\text{s}$ on each lap. Find the average velocity(in $\text{m/s}$) and average speed(in $\text{m/s}$) respectively in each lap.

• A. $20$ and zero
• B. $0$ and $20$
• C. $20$ and $20$
• D. $6.3$ and $20$

Answer 1

The correct option is B $0$ and $20$

Average velocity on each lap will be zero, because displacement is zero at the end of each lap.
$\text{Average speed}=\frac{2\pi r}{t}=\frac{2\pi \times 200}{62.8}=20\text{m/s}$