In movement analysis, power is defined as which of the following?

• A. Work = Power x Time
• B. Power = Work/Time
• C. Energy = Power x Time
• D. Power = Mass x Acceleration

Answer: (B)

Power is the rate at which work is done during movement. The defining relationship is Power = Work / Time, meaning how much work is performed per unit of time. This framing explains why power is about speed of energy transfer, not just the total amount of work. For example, doing 100 joules of work over 5 seconds yields an average power of 20 watts. The alternative expression Work = Power × Time is mathematically the same idea when rearranged, but the key concept used in movement analysis is the rate form, Power = Work/Time. If you need instantaneous power at a moment, it’s the derivative dW/dt, the rate of work at that exact moment.