Question

A 100-meter sprint is a race using only the straight side of a racetrack. A 400-meter sprint is a race that makes one complete lap around a racetrack. Why are velocity and speed the same for a 100-m sprint but not a 400-m sprint?

Answer 1

velocity is directional whereas speed is not.

On a 400-m lap, you change direction after the turn so velocity becomes negative, while speed is always positive.

Answer 2

In the 100-m sprint, the displacement is 100 meters and the distance is 100 meters. This means speed and velocity are the same for the 100-m sprint. In the 400-m sprint, the distance is 400-m, but the runners stop at the same place they start so the displacement is zero. Zero displacement means zero velocity.

Explanation: