1. Fields: Forces and Energy
Objective 1: Explain the difference between a contact and non-contact force. 

2. Force A force is a push or a pull on an object.
These forces can cause changes in an object’s motion.
Push!
…or Pull!

3. Contact Forces
Most forces you use in your everyday life are contact forces.
A contact force is a force between two objects that are touching (or in contact).

4. Examples of Contact Forces
Physical Pull!
Collisions!
Tension in a rope!
Physical Push!

5. Non-Contact Forces
You are also affected by non-contact forces every single day.
A non-contact forces is an attraction (pull) or repulsion (push) between two objects that are NOT touching.

6. Examples of Non-Contact Forces: Electric Force
Charged objects attract or repel one another even when held at some distance apart.
Opposite charges attract; similar charges repel

7. Examples of Non-Contact Forces: Gravitational Force (Gravity)
Any two objects with mass are attracted toward one another even over large distances.
The Moon is affected by the Earth even though they are not touching!

8. Examples of Non-Contact Forces: Magnetic Force
Magnetic poles attract or repel one another even when held at some distance apart.