# Homework Help: Electromagnetic force types

1. Sep 27, 2010

### xeonese

1. The problem statement, all variables and given/known data
Can anyone tell me what are the different types of electromagnetic forces? i know friction, non-penetrability of solids etc. are phenomenons of the electromagnetic force. Similarly are viscous force, cohesive force, adhesive force results of electromagnetic force?

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Sep 27, 2010

### jambaugh

I'm not sure how to answer your question. On the one hand there is only one "type" of electromagnetic force, the electromagnetic force. On the other hand there are the magnetic and electric components in a given inertial frame.

It seems you want a laundry list of common forces which are fundamentally electromagnetic. I don't know of any complete laundry list of forces. However of the four fundamental forces, if one eliminates weak and strong forces which we do not see everyday since they are short ranged (and I mean very short ranged) you are left with electromagnetic and gravitational forces. So any non-gravity force you experience will be fundamentally electromagnetic.

3. Sep 29, 2010

### xeonese

well.... to be honest, a laundry list is exactly what i wanted. eliminating every other force in the nuclear domain and gravity outside the atom, i was left only with the electromagnetic force. And that's what made me wonder whether these forces are nuthing but electromagnetic forces or not... And that laundry list is what i couldn't find anywhere. Thanks a lot for helping.

4. Sep 30, 2010

### jambaugh

(Sing to the tune of "That's Amore")

When my thumb poke your eye and you just don't know why,
That's electromagnetic!
When the cop slaps on the cuff, and then get's a bit rough,
That's electromagnetic!

Bell's will ring, ting-a-ling-a-ling, and the sound is the thing,
atom's bouncing,
but the spring in their hop is the electrons that stop
it's astounding.

....
and so on... I'll work on some more verses.

5. Sep 30, 2010

### jambaugh

Well I hate to complicate the issue but there is a caveat. In quantum theory one may refer to "a statistical force" which is not a true force but has an effect.

Since fermions cannot occupy the same quantum "state" they can "fill up" the available states and there is an effective repulsion between identical fermions. But that is more of a lack of availability of a degree of motion than a true force. It is similar to the lack of available degrees of freedom which disallows an electron to spiral into the nucleus.

This I think also contributes to the rigidity when compressing solid matter and so to the force of e.g. a slap on the face.

Bosons have a reverse statistical "force" which is behind the phenomenon of stimulated emission in lasers. "Bosons of a feather flock together" in a sense. I think this contributes to the cohesiveness of say superfluid helium (A Bose-Einstein condensate) allowing it to creep up a surface.

6. Oct 3, 2010

### xeonese

FASCINATING !!! HONESTLY !!! :rofl:

7. Oct 3, 2010

### Phrak

Go to wikipedia or elsewhere and look up Lorentz force.