# How is electric power related to electrical energy?

Apr 4, 2018

$P = \frac{E}{t}$

#### Explanation:

electrical power is the amount of electrical energy transferred in a certain amount of time.

the SI unit used to measure power is the watt $\left(W\right)$.

$1$ watt is the same as $1$ joule of energy transferred per second.

when a second passes, and $1$ joule is transferred per second, $1$ joule will be transferred in that second.

this means that the watt shows how many joules of energy are transferred in a second.

since joules measure the amount of energy transferred, and seconds measure the amount of time lapsed, the watt shows rate of energy transfer.

the rate of energy transfer is the energy transfer over a certain time.

therefore, electrical power is electrical energy over a certain time, or energy over time.

energy over time is energy divided by time, so power is energy divided by time.

this can be represented with the symbols $P = \frac{E}{t}$

where $P$ is power,

$E$ is energy,

and $t$ is time.