CEM 141 Lecture Notes - Lecture 5: Electromagnetism
Document Summary
The electromagnetic force is mediated by electric and magnetic fields. The electromagnetic force is much stronger than gravity, and can be both attractive and repulsive. We will only consider electric fields and forces between charged particles right now: this is called electrostatic force. The force between the charges can be modeled by using coulomb"s law. The electromagnetic force is much stronger and can be attractive and repulsive. Gravitational force is too weak to be detected at the atomic/molecular level. The electrostatic force stops us from falling through the earth, and makes us hover over chairs (sort of) If something is not moving, either there is no force acting on it, or the forces acting on it are equal and opposite. So we can sit on a chair because at the point the force of gravity= to the electromagnetic force. Any change in matter is accompanied by a change in energy. Changes in energy are caused by changes in forces.
