Define Power.

• A. Rate at Which Work Is Done
• B. Total Energy Expended
• C. Maximum Velocity
• D. Force Produced

Answer: (D)

Power is the rate at which work is done or energy is transferred. If you do W joules of work in t seconds, power equals W divided by t (P = W/t). Instantaneous power can also be expressed as P = F · v, the force multiplied by the velocity in the direction of motion, showing how quickly energy is being delivered at that moment. The unit is the watt (joules per second). This matters because you can transfer the same amount of energy in different amounts of time, so moving something quickly uses more power than moving it slowly. The other ideas—total energy expended, maximum velocity, or force produced—describe energy, speed, and force, respectively, not the rate of energy transfer.