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Welcome back minions!. Lots to do, so on, and so on, and so on…. What happens when…. Raining with a strong wind… Driving Home… A woodchuck with a bazooka jumps out… Slam on the brakes… Skid… Finally stop!. Friction. Friction :
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Welcome back minions! Lots to do, so on, and so on, and so on…
What happens when… • Raining with a strong wind… • Driving Home… • A woodchuck with a bazooka jumps out… • Slam on the brakes… • Skid… • Finally stop!
Friction • Friction : • A force that opposes motion between two surfaces that are touching. • For the force of friction to act between two objects, the objects must be touching.
Friction • Sliding Friction : • Sliding Friction occurs when an object slides against a surface. • When you slide an eraser over a desk the eraser will travel for a short distance and then stop because of sliding friction.
Friction • Rolling Friction : • The friction between the wheels and the surface is called rolling friction. • When you push a shopping cart through a supermarket, the force of the cart pushing back on you results mainly from rolling friction.
Friction • Fluid Friction : • Fluid friction opposes the traveling of objects through a liquid or gas. • Fluids include: Liquids (water and milk) Gases (Air and helium) Bicycle racers bend low over their bikes in order to reduce the force of fluid friction.
Friction • Static Friction : • When a force is applied to an object and the object does not move static friction has occurred. • The object does not move because the force of static friction balances the force applied. Suppose you want to move a refrigerator. You push on the refrigerator, but it does not move. The refrigerator is pushing back on you with the force of static friction.
Friction • Lubricants : • Lubricants are substances applied to the surfaces of objects to help reduce friction between them. • Lubricants include: Motor Oil, Wax, Grease
Friction • Increasing Friction : • Ways to increase friction might be making the surface rougher. • Examples: Sand scattered on icy roads to keep cars from skidding. A golfer wearing a glove to keep a good grip on the golf club.
Riddle me this… • Friction • 1) Force that pulls an object towards the center of its mass. • 2) Force that causes a change in position. • 3) A force that repels electrons. • 4) A force that opposes motion between two surfaces that are touching.
Riddle me this… • Sliding Friction • 1) When a force is applied to an object and the object does not move. • 2) Friction that opposes the traveling of objects through a liquid or gas. • 3) The friction between the wheels and the surface. • 4) This occurs when an object slides against a surface.
Riddle me this… • Rolling Friction • 1) When a force is applied to an object and the object does not move. • 2) Friction that opposes the traveling of objects through a liquid or gas. • 3) The friction between the wheels and the surface. • 4) This occurs when an object slides against a surface.
Riddle me this… • Fluid Friction • 1) When a force is applied to an object and the object does not move. • 2) Friction that opposes the traveling of objects through a liquid or gas. • 3) The friction between the wheels and the surface. • 4) This occurs when an object slides against a surface.
Riddle me this… • Static Friction • 1) When a force is applied to an object and the object does not move. • 2) Friction that opposes the traveling of objects through a liquid or gas. • 3) The friction between the wheels and the surface. • 4) This occurs when an object slides against a surface.
Homework… • Typed (not hand-written) • Full name, Period, Date • Around your house, give me examples of: • Friction • Sliding Friction • Fluid Friction • Rolling Friction • Static Friction