What is Power?

Power is how fast work is done or energy is used.

 Example: Remember that cheeseburger (~1/4 pound) I lifted up one meter to do one joule of work? If you now lift that same burger one meter in one second, you have used one watt of power. One joule per one second is one watt of power. If it took me 2 seconds, who used more power? You did of course, you worked faster. If you and I do the same amount of work but you do it twice as fast, you have used twice the power (1 watt) I have (watt). 

If P is power in watts, W is work in joules and Δt is time to do the work in seconds: 

P = W / Δt