Final answer:
When a runner completes a full lap of a 400-meter track, the distance they have covered is 400 meters, regardless of their return to the starting position.
Step-by-step explanation:
When a runner has completed one full lap around a 400 m track, the runner's distance with respect to the starting position is 400 meters. This is a simple concept of distance in a physics context. Distance refers to the total path length traveled by an object and is not concerned with the direction of travel. In this case, the runner returns to the starting position after completing the lap, but the distance they have covered in doing so is still 400 meters. Distance is a scalar quantity, which means it only has magnitude and no direction. Therefore, even if the runner is back at the start, they have traveled a considerable distance.
When a runner has completed one full lap around a 400m track, the runner's distance with respect to the starting position is 400m. This is because a lap around the track is equivalent to running a distance of 400m, which brings the runner back to the starting position. Therefore, after completing one full lap, the runner is exactly 400m away from their starting position.