Friction is a force that opposes the motion of objects in contact with each other and comes in different types including static, sliding, rolling, and fluid friction. Examples provided include humans walking using static friction between their feet and the ground, cars stopping using brakes that create friction between tires and the road, and fluids moving through pipes due to greater friction outside than inside the pipe. The document concludes by describing an activity where students will predict and test how factors like surface materials affect the motion of toy cars down ramps.

1. Friction

2. What is friction?
What do you think friction is?
Take an educational guess...

3. Educational Guess
✴Friction is a force that opposes motion.
✴Makes it difficult for an object to move across a
surface
✴The action of one surface or object rubbing against
another.

4. Friction is everywhere!
• Friction is everywhere
Can you give me examples where I can find
friction?
• Let’s think about it!
Friction occurs every day in our daily lives

5. Examples of Friction
• Humans being able to walk--we use friction
to move!
Sitting in a chair and not slide off the
chair--friction keep us sitting in our seats
• We can keep our hands warm by ______??

6. Examples of Friction
• We can keep our hands warm by RUBBING
them together fast.
• Let’s try this!!

7. Examples of Friction
• Cars stop by using breaks--which use
friction to stop the rotation of the wheels
Trains have steel wheels and run on steel
tracks--which its weight and friction allows
the wheel to turn
• Car tires operate on the road--Why?
Because of friction--tires rubbing the road
creates friction.

8. Types of Friction?
• Rolling friction
Static friction
• Fluid friction
Sliding friction

9. Rolling Friction
• The resistance between two surfaces
Example:
• Tire rolled one way but the road was still

10. Static Friction
• Friction is between two surfaces that are not
moving past each other
Example:
• When the balloon is rubbed on your
hair...Static friction is created!

11. Fluid Friction
• When an object is moving in liquid or gas
Example:
When you drink from a straw, the fluid
inside the cup was forced to go through the
straw...Why? Because GREATER FRICTION

12. Sliding Friction
• The force that opposes the motion of two
surfaces that past each other
Example:
• When you go down the slide, you create
sliding friction

13. Let’s look at a video!
http://www.youtube.com/watch?v=Zlhyw8fU1hI

14. Today’s Activity...
• We are predicting and testing an
experiment!
Materials: toy cars, ramps, towels, masking
tape, paper, pencils, stop watch (timer), and
calculator.
• The question is what are we going to do with
these materials today?
Let’s think about!

15. Give up?
Let’s begin the race!!

16. After Activity...Review
Game
Let's Review!