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 and average speed for each complete lap.

• A. $10\text{m/s}$ and $20\text{m/s}$
• B. $0\text{m/s}$ and $20\text{m/s}$
• C. $20\text{m/s}$ and $20\text{m/s}$
• D. $0\text{m/s}$ and $10\text{m/s}$

Answer 1

The correct option is B $0\text{m/s}$ and $20\text{m/s}$

Average velocity on each lap will be zero, because displacement is zero.
$\text{Average Speed}=\frac{\text{Total distance travelled}}{\text{Total time taken}}=\frac{2\pi r}{t}=\frac{2\pi \times 200}{62.8}=20\text{m/s}$