What's the difference between electrostatic and electromagnetic?

As in the forces? We talk about electrostatic replulsion between protons, but I thought electricity and magnetism were part of the same force?

Reply 1

teachercol

They are. Electrical forces are what you get with static charges. Magnetic forces are you get with moving charges.

Simpler to just refer to electromagnetic forces.

Reply 2

physicsgirlie

teachercol

Electrical forces are what you get with static charges. Magnetic forces are you get with moving charges.

Why is this?

Reply 3

teachercol

Currents are just moving charges.

Charges -> electrical forces
Currents - > magnetic forces

Reply 4

physicsgirlie

Ah right! Thanks :smile:

Reply 5

F1 fanatic

They're also interchangeable... an electric field creates a moving charge which itself generates a magnetic field. Interesting but fairly pointless fact, is that if you are in the rest frame of the electron the electrostatic and magnetic forces swap over... so what was the electric field becomes a magnetic field and vice versa. It's a relativistic effect.

the word static really refers to the fact that they are not changing in time... so all the time dependence of the equations disappear. You can have magnetostatics too. electrostatics are therefore easier to deal with mathematically.

Reply 6

Morbo

teachercol has provided the pragmatic answer.

However, from a relativistic point of view, there is actually only the Coulomb (electrostatic) potential. Magnetic forces are caused by the nature of space-time...which is cool, I think.