Presentation on theme: "+ Make a Prediction!!! “Two objects of the exact same material are placed on a ramp. Object B is heavier than object A. Which object will slide down a."— Presentation transcript:
+ Make a Prediction!!! “Two objects of the exact same material are placed on a ramp. Object B is heavier than object A. Which object will slide down a ramp as the angle of the ramp increases”
+ Lets Determine for static Friction using the two methods we know! As a class we will calculate the static friction co-efficent using the angle method; raising the angle until the object moves. We will also use the force method; measuring the force needed to move the same object on flat ground.
+ Group Work Each Table will break into 2 groups Each group will solve assigned problem The Table will share their solution with the other half
+ Practice Problem #1 It takes 50N to pull a 6.0 kg object along a desk at constant speed. What is the coefficient of friction?
+ Practice Problem #2 The coefficient of sliding friction between two materials is 0.35. A 5.0 kg object made of one material is being pulled along a table made of another material. What is the force of friction?
+ Practice Problem #3 A packing crate is placed on a plane inclined at an angle of 35° from horizontal. If the coefficient of static friction between the crate and the plane is 0.65, will the crate slide down the plane?
+ Practice Problem #4 A piece of wood is sliding on a steel table saw ( k =0.25) is pushed with a force of 50N. If the wood is moving at constant velocity, what is the mass of the wood?
+ Practice Problem #5 A 800-N student is Rollerblading at a velocity of 6m/s [W] when the student trips and slides horizontally along the trail, coming up to stop in 1.5 seconds. a. Determine the Student’s average acceleration. b. What is the kinetic friction as the student slides? c. Determine the coefficient of kinetic friction between the student and the trail.
+ Practice Problem #6 A 1640-kg lift truck with rubber tires is skidding on wet concrete with all four wheels locked. The static friction coefficient is 0.7 and the kinetic friction coefficient is 0.5. Calculate the acceleration of the truck.