Electromagnetic force and resistance to displacement of atoms.

[PrincePhoenix]

It is written over here http://www.particleadventure.org/electromagnetism.html that,
"...the force that keeps you from falling through the floor is the electromagnetic force which causes the atoms making up the matter in your feet and the floor to resist being displaced."
Can anyone explain how the electromagnetic force causes the atoms resist being displaced?
And how does it cause friction?

 

[Bob_for_short]

It is easy. Atoms interact with some sort of a potential force U(r) (a complex result of quantum mechnaical effects).
At small displacements from the equilibrium positions the potentials U(r_i) can be represented as quadratic ones => the forces are elastic (F=-kx) and returning. So any external force makes atoms displace until their new equilibrium positions where the elastic reaction force compensates the external force. QM is very important here - for atom stability.

 

[astrokreng]

The electromagnetic force is one of the four fundamental forces of nature, along with gravity, strong nuclear force, and weak nuclear force. It is responsible for the interactions between charged particles, such as electrons and protons.

In the context of atoms, the electromagnetic force plays a crucial role in keeping the structure of matter intact. Atoms consist of a nucleus made up of protons and neutrons, surrounded by orbiting electrons. The electrons are negatively charged, while the protons are positively charged. The electromagnetic force between these particles is what holds the atom together and prevents it from collapsing.

When an external force is applied to an object, such as when you stand on the floor, the atoms in the object experience a displacement. However, the electromagnetic force between the particles resists this displacement, keeping the object's shape and structure intact. This is why you do not fall through the floor, as the atoms in your feet and the floor are constantly interacting through the electromagnetic force.

The electromagnetic force also plays a role in causing friction between two surfaces. Friction is the resistance that occurs when two objects move against each other. As the atoms on the surface of one object come into contact with the atoms on the surface of another object, the electromagnetic force between them causes them to stick together. This creates a force that resists the motion between the two surfaces, resulting in friction.

In summary, the electromagnetic force is responsible for the stability and structure of atoms, which in turn allows for the resistance to displacement and the occurrence of friction between objects. This fundamental force plays a crucial role in our everyday lives and is essential for understanding the behavior of matter at a microscopic level.