Types of Forces

Forces can be classified into different types depending on

Fundamental Forces

Gravitational Force
$$ \vec{F}=-\frac{GmM}{r^2}\hat{r} $$
Electric Force
$$ \vec{F}=\frac{1}{4\pi\epsilon} \frac{qQ}{r^2}\hat{r} $$

Phenomenological Forces

Phenomenological motion is constraining motion that results from complex interactions between objects the force is observed and found experimentally

Static Friction: Negates motion parallel to a surface
Kinetic Friction: Opposes motion parallel to a surface
Normal: Opposes motion normal to a surface
Tension: Constraint of a string, force in direction in the direction of a string at its length
Spring: Constraints of a spring, force in direction opposite to the resting position

Example