1. Types of Friction

2. Types of Friction Kinetic Friction Is friction between moving surfaces
Sliding
Rolling
Fluid

3. Types of Friction Static Friction
When a force is applied to an object but does not cause it to move

4. Pushing Books
Try pushing a pile of five books across your desk with one finger
Place some pencils under the books, is it easier or harder to move the books now?

5. Ways to Reduce Friction
Switching From sliding kinetic friction to rolling kinetic friction
Example: Placing a large, heavy box on a cart with wheels to move it instead of pushing it

6. Ways to Reduce Friction
Lubricants: Substances that are applied to surfaces to reduce friction between surfaces
Example: Butter in a pan while cooking so that food does not get stuck
Example: Adding water to a slide will make you go faster because the friction is reduced

7. Soapy Hands
Who can open a pickle jar? (or a jelly jar, or a cherry jar, or whatever kind of jar you wish!) 
Who can open a pickle jar with soap on their hand?
It is easier or more difficult with soap?

8. Ways to Increase Friction
Make surfaces rougher
Putting salt on patches of ice in the winter so that you do not slip
Wearing gloves in football so that you can catch the ball more easily

9. Ways to Increase Friction
Increase the force pushing the surfaces together
Pressing down harder while scrubbing a pan
Sanding wood with sandpaper will work better if you are pressing down with more force

10. With your groups
Think of 3 examples where you can increase friction between 2 objects
Think of 3 examples where you can decrease friction between 2 objects
*They cannot be the same examples we have used in class!! *

11. Exit Slip Turn in to Ms. Crema to get your homework for the day!
What is Friction?
What are the 2 factors that affect the amount of friction between objects?
What is one way we increase friction between 2 surfaces?
What is one way decrease friction between 2 surfaces?