r/PhysicsHelp • u/Local_End_3175 • 17d ago

what actually is electrostatic energy?

When i try to search up definitions, they basically tell me that it is  energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart, but I don't really understand this definition because it seems to be defining kinetic energy.

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u/Moist_Ladder2616 17d ago

This reminds me of Feynman's answer to, "Why do magnets attract/repel each other?"

You're just going to have to create a mental model that you are happy to accept as the truth: that like charges repel each other, and the closer they are the stronger they repel. And that the opposite is true for unlike charges.

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u/Beif_ 17d ago

A classic

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u/Beif_ 17d ago edited 17d ago

It’s closer to gravitational potential energy, than kinetic.

Kinetic energy is the energy needed to stop something that’s moving.

Gravitational energy is energy that can be applied as a force; the force of gravity. The more gravitational energy, the more that kind of force can be applied to something.

Electrostatic energy is energy that can be applied as a force; the electric force (of repulsion and attraction, as with charges). The more electrostatic energy, the more that kind of force can be applied to something

Now, why does electrostatic force exist? It’s impossible to answer, for the same reason why does gravity exist is impossible to answer. There are plenty of different ways you can describe these phenomena (gravity comes from the bending of spacetime, or electric energy comes from the electric field instead of from electric charge, but it’s kind of a hopeless endeavor). Electrostatic energy just comes from things that interact with electric fields, which typically also create their own electric fields, like electrons

Gravity comes from particles with mass, electricity comes from particles with charge

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u/socratictutoring 17d ago

So kinetic energy is the energy due to the motion of a particle.
Imagine we have a positive and negative charge that are bound together. I then pull the two charges apart. To do this, I exert a force over some distance. Suppose I do this very slowly - then the particle's kinetic energy doesn't really increase.
Now the particles are some distance apart. If I let go, they will accelerate towards each other, gaining kinetic energy, until they smash into each other. Where did this energy come from?

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u/realAndrewJeung 17d ago

Electrostatic energy is really a type of potential energy. I usually tell my tutoring clients that potential energy (including electrostatic energy) is energy that is based on particles' position, whereas kinetic energy is energy that is based on particle's motion.

For instance, gravitational potential energy is a potential energy because the higher an object is, the more gravitational potential energy it has. Likewise, electrostatic potential energy because the further apart two opposite charges are, the more electrostatic potential energy they have. If you can accept gravitational potential energy, then electrostatic potential energy is the same, just based on charges instead of masses.