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…

CUBE Activity

(Good idea to draw first, then assemble later!)

• A cube has 6 sides, so here is what you need to draw:

• 1 side = Name (First and Last CLEARLY PRINTED)• 1 side = Definition of Friction• 1 side = drawing of Sliding Friction• 1 side = drawing of Fluid Friction• 1 side = drawing of Rolling Friction• 1 side = drawing of Static Friction

• Due Tuesday, March 17th!