I'm learning electrostatics right now in college physics 2, and I'm struggling to understand what "electrostatics" exactly specifies. My professor told me that "when charges are at rest in our frame of reference, they exert electrostatic forces on each other ", but what does it mean that the charges are at rest in our frame of reference? Does that mean that point charges are not physically flying around in space? Like the "radius" value in couloumb's law between two charges is not changing? Or does charges being at rest mean that there is no 'flow' of charges like two metal balls w/ charge 2 couloumbs and -3 couloumbs being brought into contact and obtaining -0.5 couloumbs each?
What happens to Coulomb's law and Gauss's law when charges are not at rest?
Also, why is the electric field inside a conductor zero? This sort of branches out from the definition of "being at rest". My textbook says that "If there is an electric field inside a conductor, the field exerts a force on every charge in the conductor, giving the free charges a net motion. Since by definition electrostatic situation is one in which charges have no net motion, the electric field inside the conductor must be zero". What does that mean? If there is an electric field inside conductor the electrons will be flying out of the conductor?