Electromagnetism

Electromagnetism is the study of electric fields and magnetic fields and how they interact.

Electric Fields

An electric field is produced by any electric charge. If there is no charge, there is no field. In the real world, electric charges are all around us so there is always an electric field around us. If two electric charges would collide together or push away from each other with some force, the field tells us what force would happen if you placed a charge in a certain spot in space and time. That is why if there is a charge, there will be a field because any second charge you add will be attracted or pushed away by the first charge. The force experienced by any two charges can be expressed by k_e*(q*Q)/(r²). We label charge as q or Q depending on which is bigger. This essentially says that the force between these two charges is proportional to both of the charges thus q*Q and the force gets smaller the farther away they get thus you divide by the distance r between them and because of the Newton’s third law pair, both charges feel an equal force but have to factor in both their distances which both equal r in this notation. Therefore, you divide by r². This is only a rough approximation of the force experienced and will later be expressed in an integral to take care of what happens when charge is not uniform.