## Energy and Pricing

You can calculate the power and energy in a circuit using the following equations:

In these equations power is measured in Watts, Energy in Joules and time in seconds.

If you wanted to use this equations to calculate the amount of energy used by a household you'd end up with numbers that were far too large: instead we use the 'units' of electricity or kilowatthours which means that a kW of energy has been used for an hour. The equation then becomes:

If you wanted to use this equations to calculate the amount of energy used by a household you'd end up with numbers that were far too large: instead we use the 'units' of electricity or kilowatthours which means that a kW of energy has been used for an hour. The equation then becomes:

Now, to find the price of your energy bill, you simply multiply the price per unit or kWh by the number of kWhs.