2. Types of friction What is friction? Unbalanced force that slows objects down Important to understand to use Newton’s laws as friction in almost all real-life situations Types of friction: Static friction Sliding friction Rolling friction Air resistance
3. Static friction Friction prevents an object from moving when force is applied Tries to keep an object at rest Ex: walking Every step you take pushes against the Earth Without friction, you would slip and fall with each step What happens when the net force is greater then the force of static friction?
4. Sliding friction Slows down an object that slides Ex: if you push a box across the room, there is sliding friction between the bottom of the box and the floor Ex: Rubbing hands , shuffling shoes
5. Types of Friction ROLLING FRICTION Allows wheels to turn by pushing back so tire moves forwards Ex: bicycle, car Ex: when you ride your bike through water, there may not be enough friction between the tire and the ground to move forward, and so the bike skids (slides off balance) AIR RESISTANCE Air pushes against you Acts on the forward-moving part an object Ex: front of a car Ex: when you ride the bicycle, the air pushes the your hair and clothes back