Understanding the Difference

* Velocity: Velocity is a vector quantity, meaning it has both magnitude (speed) and direction.

* Speed: Speed is a scalar quantity, meaning it only has magnitude (how fast something is moving).

The Scenario

Imagine a runner completing a lap on a circular track. Here's why they can have zero average velocity but non-zero speed:

* Non-zero Speed: The runner is constantly moving, so they have a non-zero speed throughout the lap.

* Zero Average Velocity: Since the runner starts and ends at the same point, their displacement (the change in position) is zero. Average velocity is calculated as displacement divided by time, so their average velocity for the lap is zero.

Example

Let's say the runner completes a 400-meter lap in 60 seconds:

* Speed: Speed = Distance / Time = 400 meters / 60 seconds = 6.67 meters/second.

* Displacement: Displacement = 0 meters (starts and ends at the same point).

* Average Velocity: Average Velocity = Displacement / Time = 0 meters / 60 seconds = 0 meters/second.

In Conclusion

A body can have zero average velocity if it returns to its starting position, even if it has been moving at a non-zero speed throughout its journey. Think of it like a round trip – you might cover a lot of distance, but if you end up back where you started, your overall displacement is zero.