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