1. Four Fundamental Forces of the Universe Notes

2. We are trying to understand this system.
If we identify the forces acting in the system, we will be able to understand the causes behind the effects that we are seeing.

3. There are four major forces in the Universe:
1. Strong force
2. Weak force
3. Gravity
4. Electromagnetic forces (electricity and magnetism go together)

4. Strong and Weak Forces
They have to do with forces in the nucleus of Atoms, and you’ll learn about them more next year.
But since you asked, the Strong force holds positive protons tightly together in the nucleus, and the weak force is involved in the forces that change quarks from one kind to another?

6. But we are focusing on Gravity and Electromagnetic forces!

7. Gravity
The forces that pulls objects to a center point. Strength of the force is based on the masses of the objects, and the distance between them.
It is only an attractive force
It is the weakest of the four forces
The fields go out forever.

8. Electromagnetic forces
The forces of attraction and repulsion between charged particles. The strength of the force depends on the amount of charge and the distance between objects.
It is the 2nd weakest of the four forces
The fields go on forever.

9. The 4 forces can explain the structure and behavior of SYSTEMS in the Universe! So far…
Such as electromagnetic charges causing bonds between atoms in a molecule
Such as gravity causing planets to be round.
Such as electromagnetic polarity causing water to attract itself.

10. SYSTEM: a set of connected things or parts forming a complicated whole
Parts of atoms form a system.
Forces forming a ball of water in space are a system.
A towel, PVC pipe, and a soda can form a system.

11. Good Models 1. Should label all the parts of the system
2. Should label the forces in the system
3. Should explain how the forces in the system cause the action and behavior of the system.

12. For your test, you will be using models, and making models a lot!