Friction

What is friction?

Take an educational guess...

What do you think friction is?

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.

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

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 ______??

Examples of Friction

• We can keep our hands warm by RUBBING them together fast.

• Let’s try this!!

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.

Types of Friction?

• Rolling friction

Static friction

• Fluid friction

Sliding friction

Rolling Friction• The resistance between two surfaces

Example:

• Tire rolled one way but the road was still

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!

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

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

Let’s look at a video!

http://www.youtube.com/watch?v=Zlhyw8fU1hI

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!

Give up?

Let’s begin the race!!

After Activity...Review Game

Let's Review!