1. Universal Forces

2. Electromagnetic Forces
Electromagnetic Forces have to do with charged particles
These are the only forces that can attract and repel
For electric forces, this is a force between charged particles like protons or electrons (this will be talked about more in electricity)
Magnetic Forces occur only on certain metals
For magnetic force like poles repel and opposites attract

3. Nuclear Forces
Nuclear forces occur within the nucleus of an atom, these forces hold the nucleus together
The strong nuclear force holds protons and neutrons together, though this force acts over VERY short distances it is an EXTREMELY powerful force
The weak nuclear force is much less powerful but works over a greater distance

4. Gravitational Forces Gravity is the weakest universal force
Gravitational Force is an attractive force that occurs between any two objects
This being said, EVERY OBJECT ATTRACTS EVERY OTHER OBJECT in the universe
Note that this gravitational force may not be felt unless the mass of the object is EXTREMELY large
Hence the larger the object or the closer two object’s are the greater the gravitational force between them

5. Gravitational Forces
Gravitational forces are effective over long distances
Think about it, how far is the Earth from the sun, yet it is still effected by the sun’s gravitational force
The moon orbits the Earth because of gravity
Gravity pulls on the moon causing it to travel in a circle, this type of force is called centripetal force
Centripetal force is a center directed force that continuously changes the direction of an object causing it travel in a circle
Please note there is NO SUCH THING as centrifugal force