## Power

Power is basically the rate at which we do work. The work done in a unit of time is called power. Watt (W) is the SI unit of power. Watt is also called joules per second. Average power is the consumption of total energy divided by the total time taken.

The equation that we used to calculate power is work done/time.

A work of 55 joules is done by a car in 5 seconds. What is the power generated by the car?

- Putting the values into the equation, 55/5 = 11 watts.

An 11 watts kettle is turned on for three hours. What is the work done by the kettle?

- Putting it into the equation, 11 = work done/ 3 x 60. Work done = 1980 joules.

A 12 watts bulb is turned on for three hours. What is the work done by the kettle?

- Putting it into the equation, 12 = work done/ 3 x 60. Work done = 2160 joules.