1. Week

2.  Student will:  Incorporate Force of Friction into calculation  Static Friction  Kinetic Friction

3. Questions 1)How is friction define? Know how to calculate Normal Force

4. Two Kinds Of Friction Coefficients not Use if two surfaces are not moving Use if two surfaces are moving

5. Example: Friction The Flash is pulling a car, that weighs 1,200 kg, to a nearby gas station and makes the car accelerate at 10 m/s 2. Assume friction and the coefficient of kinetic friction "µ k " is 0.9. Compute the Flash’s applied force on the car.

6. The Flash is pulling a car, that weighs 1,200 kg, to a nearby gas station and makes the car accelerate at 10 m/s 2. Assume friction and the coefficient of kinetic friction ("µ)" is 0.9. Compute the Flash’s applied force on the car. Steps 1)Define

7. Choose an equation or situation: Rearrange the equation to isolate the unknown: 2)Plan

8. Substitute the values into the equation and solve 3)Calculate

9. The Flash’s applied force is 22,584 N. 4)Evaluate

10. Example: Coefficients of Friction When Colossus pushes a 2000 kg shipping box resting on a road, he exerts a force of 1800 N to start it sliding. Once it is sliding, he uses a force of only 1500 N to keep the shipping box moving with constant speed. What are the coefficients of static and kinetic friction between the shipping box and the road?

11. Steps 1)Define When Colossus pushes a 2000 kg shipping box resting on a road, he exerts a force of 1800 N to start it sliding. Once it is sliding, he uses a force of only 1500 N to keep the shipping box moving with constant speed. What are the coefficients of static and kinetic friction between the shipping box and the road?

12. Choose an equation or situation: Rearrange the equation to isolate the unknown: 2)Plan F n = mg because it is on a horizontal surface

13. Substitute the values into the equation and solve 3)Calculate Coefficient of frictions do not have units

14. The coefficient of static friction is.092 and coefficient of kinetic friction is.076. 4)Evaluate