Units of Electric Charge

The SI unit of charge is the Coulomb.

Both a proton and an electron have a charge of

1.60217662 × 10-19 coulombs

With a proton having a positive charge with this magnitude and an electron having a negative charge of this magnitude.

An Amphere-Hour is 3600 multiplied by one Coulomb.

Let me know if you have questions about the units of electric charge.

Relation Between Power and Energy (Physics)

There are many forms of energy. Various types of potential energy, kinetic energy, etc.

Energy can be converted between different forms.

Let’s start with a different example though, to understand the relation between power and energy.

Distance and velocity.

Distance is described in units of meters and velocity is described in units of meters per second.

So the difference between distance and velocity is that velocity is divided by time.

With power and energy, power is units of energy divided by time. The same difference as distance and velocity.

The units of power are watts, the units of energy are joules. A watt is one joule divided by one second.



What is the difference between energy and power?

-Power is energy divided by time. Often units of J/s (joules/second). These are known as Watts. 1 W = 1 J/s

When calculating the amount of electrical energy, you multiply electrical power times what?

-You multiply the power by the time (be aware of the right units for the situation) to get energy

What are the differences between energy and electricity?

-There are many types of energy, the electrical energy from an electric potential is one type of energy.

What does power measure?

-Power measures energy per time. So joules per second is one expression of power. A kilowatt is 1,000 watts.

What is the equation to calculate power?

-That depends on the situation.

What is the difference between watts and kilowatts?

-A kilowatt is 1,000 watts, much like a kilometer is 1,000 meters.

What is the relationship between power and energy and time?

-If you multiply power by time, you get energy. If you divide energy by time, you get power.

P = E/t

You can rearrange that equation in a few ways.