What forces affect point charges?

I am working on a point charge simulator, and I was wondering what forces can affect point charges (assuming that they operate in a closed system, with no externally generated light, and initial velocities). I have thought of the following "classes" of forces so far:

• Electric Field
• Magnetic Field
• Gravitational Field
• Linear Momentum
• Kinetic Energy

Thanks!

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Physics can model only 4 kinds of forces: electromagnetic, strong nuclear, weak nuclear and gravitational force. Momentum and Energy are not forces, but every particle has momentum (linear and/or angular) and energy (rest energy, potential energy associated with the forces, and kinetic energy). – Ana Dec 29 '12 at 2:36

Particles with charge experience electric and magnetic forces, and particles with mass can also experience gravitational forces.

However, keep in mind that linear momentum and kinetic energy are not forces, and if you write your simulator correctly, you will probably not need to worry about these quantities. Rather, conservation of momentum and energy will arise naturally from your simulation. For example, if you model the forces of an electron in an electric potential, you will find that the total energy of the particle at any given time is the same as the initial energy of the particle.

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If point charges have no mass, only electric and magnetic field. If point charges have mass, then electric, magnetic & gravitational field, linear momentum and kinetic energy play a role.

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