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An athlete runs around a 400 meter track in 60 seconds, starting and finishing at the same place. What is her speed and velocity in m/s?

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Correct Answer: A. Speed = 6.67 m/s and Velocity = zero
Speed is a scalar quantity involving magnitude only: Speed = distance/time = 400/60 = 6.67 m/s. Velocity is a vector quantity involving both magnitude and direction: Velocity = displacement/time = 0/60 = zero.
Distance traveled is not dependent on a direction, but displacement is. Displacement = distance from the finish to the start, which in this case is zero as the athlete has run around an oval to arrive back at her starting place.
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