#Goals: SWBAT...
1. Describe which friction coefficient refers to moving objects, and which refers to objects at rest
2. Draw accurate FBD's
3. Solve problems involving kinetic and static friction AND ACCELERATION
Warm-Up (5min)
Copy the following, then draw the FBD and list all the given and unknown information.
CLASSWORK
1. #036A: An Example of how to solve a Friction Problem, plus some Practice Problems
A. We will solve the warm-up problem together, then you'll solve a few problems on your own
Take notes as we solve
B. Solve these on your own:
Theory Question:
2. Ryan is moving to a new apartment and puts a dresser in the back of his pickup truck. When the truck accelerates forward, what force accelerates the dresser? Under what circumstances could the dresser slide? In which direction?
Math Questions:
3. You apply a 98N force on a 25kg wood box sliding across a wood floor. What is the resulting acceleration?
FYI: for wood on wood, µs = 0.50 and µk = 0.20 ANSWER: 2.0m/s2
4. You help your mom move a 41-kg bookcase to a different place in the living room. If you push with a force of 65 N and the bookcase accelerates at 0.12 m/s2, what is the coefficient of kinetic friction between the bookcase and the carpet? ANSWER: µk=.15
5. Shuffleboard is like curling, but for old people. A shuffleboard disk is accelerated to a speed of 5.8 m/s and released. If the coefficient of kinetic friction between the disk and the concrete court is 0.31, how far does the disk go before it comes to a stop? The courts are 15.8 m long. ANSWER: 5.5m
At Home Learning (HW)
1. Complete the problems from #036A
2. #036B: Watch/take notes/complete edPuzzle on the following:
A. (2:57) Everybody Brought Mass to the Party! - EDpuzzle
B. (7:10) Introduction to Work with Examples - EDpuzzle