Average Velocity Calculation

The question asks for the average velocity of Reshma. It's important to distinguish between average velocity and average speed.

• Average speed is calculated using the total distance covered divided by the time taken.
• Average velocity is calculated using the total displacement divided by the time taken. Displacement is the net change in position from the start point to the end point.

Understanding Displacement

Reshma swims in a 120 m long pool. She covers a total distance of 240 m. This means she swam the length of the pool (120 m) and then swam back to her starting point (another 120 m). Since she finished at her starting point, her net change in position (displacement) is 0 meters.

Calculating Average Velocity

The formula for average velocity ($v_{avg}$) is:

$ v_{avg} = \frac{\text{Displacement}}{\text{Time}} = \frac{\Delta x}{\Delta t} $

Given:

• Displacement ($\Delta x$) = 0 m (since she returned to the starting point)
• Time ($\Delta t$) = 1 minute = 60 seconds

Substitute the values into the formula:

$ v_{avg} = \frac{0 \text{ m}}{60 \text{ s}} $

$ v_{avg} = 0 \text{ m/s} $

Therefore, Reshma's average velocity is 0 m/s.