5k views

### What is the cause of the normal force? [duplicate]

I've been wondering, what causes the normal force to exist? In class the teacher never actually explains it, he just says "It has to be there because something has to counter gravity." While I ...
1k views

### Is the electromagnetic force responsible for contact forces? [duplicate]

It is commonly stated that there are four fundamental forces, or interactions, in nature. It is natural to consider which of those is responsible for the normal force we meet in elementary physics. ...
698 views

### Proof that the ground pushes you up [duplicate]

It has been said that when you try to jump you are exerting your force on the ground and the ground pushes you up. I was wondering if this was an over-simplification or not. If so, what's the full ...
1k views

### Where does the Pauli Repulsive Force come from that counteracts the attraction between atoms and ions? [duplicate]

I'm learning about such things as ionic and covalent bonds, and the reason given for the ionic bonds is electrostatic attraction. However, if that were true, then the two ions would accelerate toward ...
928 views

### What kind of force is it when you push a door shut? [duplicate]

Possible Duplicate: How can I stand on the ground? EM or/and Pauli? It probably seems like a silly question to a physicist, but I'm from a pure maths background and don't know an awful lot ...
111 views

### Falling through the ground [duplicate]

I do not know much about physics but I know that according to Newtons third law of motion when we walk we are pushing the ground down but the ground is pushing us up. What force is making the ground ...
59 views

### Is it degeneracy pressure rather than electrostatic repulsion that stops us falling through the floor? [duplicate]

From Wikipedia: Degeneracy Pressure Freeman Dyson showed that the imperviousness of solid matter is due to quantum degeneracy pressure rather than electrostatic repulsion as had been previously ...
402 views

### How does the Pauli exclusion principle create a force in degenerate matter?

My understanding is that when it comes to forming a white dwarf, it is the electron degeneracy pressure, due to the Pauli Exclusion Principle, preventing collapse in of the white dwarf. If the ...