Question

Usha swims in a $90\mathrm{m}$ long pool. She covers $180\mathrm{m}$ in one minute by swimming from one end to the other and back along the same straight path. Find the average speed and average velocity of Usha.

Answer 1

Step1: Given data

The length of the pool = $90\mathrm{m}$.

Distance Usha covers = $180\mathrm{m}$.

Time she takes = $1\mathrm{minute}=60\sec$.

Step2: Average Speed and Average Velocity

Average speed = $\frac{\mathrm{total}\mathrm{distance}}{\mathrm{total}\mathrm{time}}$.

Thus, average speed = $\frac{180}{60}=3\mathrm{s}$.

Now, average velocity = $\frac{\mathrm{displacement}}{\mathrm{total}\mathrm{time}}$.

Since Usha returns to its initial point from where she started her displacement is zero.

Thus, the average speed $=3\mathrm{s}$. and Average Velocity of Usha are zero.