Power from Work

Power tells you how quickly work is being done. If the same amount of work is done in less time, the power is larger because the energy is transferred or used more rapidly. This formula comes from dividing the amount of work by the time taken, so its unit is the watt (W), which means one joule per second.

Use this when you know how much work or energy was transferred and how long it took. It is common in mechanics, machines, engines, and any problem involving energy use over time.

• Using the wrong time unit instead of seconds
• Forgetting that power is work divided by time, not multiplied by time
• Mixing up work with force or energy without checking the units