Let’s see how power is related to force and speed. Consider a car moving uphill with a constant speed v. As the car travels a distance s, the work done by the engine is W = Fs, and the power it delivers is

Since the car has a constant speed, v = s/t, it follows that

p = Fv

For example, suppose you push a heavy box with a given force. You produce twice as much power when you push at 2 m/s than when you push at 1 m/s. Similarly, if you push a box at a given speed, you produce twice as much power if your force is 40 N rather than 20 N. The connection between power, force, and speed is very straightforward.