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:

In the 100meter sprint, the race is in a straight line, so the distance and displacement are the same, making speed and velocity equal. In a 400meter sprint, the runner ends at the starting point, so the displacement is zero. Speed is calculated using distance, but velocity is calculated using displacement, so the velocity for the 400meter sprint is zero while the speed is not.