Physics Bootcamp

Experiments show that there are four {\bf fundamental forces} in nature that can explain all other forces.

The weak and strong nuclear forces are short-range forces, becoming significant only at nuclear distances. We will not study the nuclear forces in this course.

The electromagnetic and gravitational forces are long-range forces. The electromagnetic force lumps together electric force and magnetic force since both are related to the same property of matter, i.e. the electric charge.

Besides these fundamental forces, we encounter many other forces in everyday life which are fundamentally caused by gravitational and/or electromagnetic force. For instance, the force of friction between two solid surfaces is an average effect of the electric force between the electrons and protons of the two surfaces in contact. Similarly, the force applied by a spring, the force of tension in a string, the force of air resistance, and the force due to surface tension in a fluid, just to name a few of common application, all have their basis in the electric force.

We will be working in the SI system of units, in which the unit for force is Newton, abbreviated by capital letter \(\text{N}\text{.}\) How big is a \(1 \text{ N}\) force? Using the second law of Newton, we can say that \(1 \text{ N}\) force on a \(1 \text{ kg}\) object will cause the object to accelerate at \(1\text{ m/s}^2\text{.}\)