The correct answer is:

a. They return to the starting point.

Explanation:

The average velocity is defined as the displacement divided by the total time. Displacement is a vector quantity, representing the shortest straight-line distance between the starting and ending points.

• In a circular lap, the runner starts and ends at the same point. Hence, their displacement is zero.
• Since displacement is zero, the average velocity, which depends on displacement, also becomes zero, regardless of the total time or the speed of the runner.

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Would you like further details or have questions about this concept? Here are related queries for deeper understanding:

1. What is the difference between velocity and speed?
2. How is average speed calculated, and why isn’t it zero for this case?
3. Can the average velocity ever be non-zero for circular motion?
4. How does the time taken to complete the lap influence the instantaneous velocity?
5. What is the role of direction in determining velocity?

Tip: Always remember that velocity depends on displacement (not the path length), while speed depends on the