The unit
for measuring energy in the metric system is the Joule (J)
or a newton meter (N m). The equations for various kinds of
energy yield joules, for example:
In order
to determine the energy used by an appliance, you also need
to know how long, or the time, that it was turned on. The
unit of the watt is a unit of power, or the energy used per
time. The equation for power is:
The unit
of a joule of energy is a very small amount of energy and
therefore the watt is a very small amount of power. While
many appliances are rated in watts, it is common to see power
measured in kilowatts (kw) or thousands of watts.
Rating
Your Appliance
