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!
