Mr. Smith is designing a race where velocity will be measured. Which course would allow velocity to accurately get a winner?

a 5 mile course from the center of town heading north to the outskirts of town
a 100 meter swim in a 50 meter pool
a 2 mile run around a 400 meter track
a 10 mile bike course that zigzags through the mountains and back again

The 2 mile run around a 400-meter track would allow velocity to accurately determine the winner. Velocity is a measurement of speed in a specific direction, and in this case, the race on the track provides a clear and measurable direction. The 5-mile course from the center of town, the 100-meter swim, and the 10-mile bike course do not provide a clear or measurable direction.