In physics, which set of quantities is required to determine mechanical power?

• A. Force exerted
• B. Distance moved
• C. Time required
• D. Force exerted, Distance moved, and Time required

Answer: (D)

Mechanical power is the rate at which work is done. To calculate average power you must know how much work is performed and the time over which it happens. Work equals force times distance moved (W = F × d) when the force acts along the direction of motion. Therefore average power is P = W / t = (F × d) / t. This shows you need the force, the distance moved, and the time to determine power. If the force isn’t exactly aligned with the motion, use the component along the motion (W = F cosθ × d). For instantaneous power, P = F · v, which also ties together force and speed (distance per time).