1. Teaching Point: “To make connections between friction and machines.”
Do now Discussion: When you rub your hands together, you are doing work. You are exerting a force up and down over a (small) distance.
How could you make doing this work easier? How could you make it more difficult? Explain.

2. TP: “To make connections between friction and machines.”
Friction Reduces Work
Friction- a resistance force created between two surfaces.
Friction makes doing work (i.e. moving an objects) in a machine more difficult

3. Friction Creates Heat Friction usually creates heat
TP: “To make connections between friction and machines.”
Friction Creates Heat
Friction usually creates heat
The kinetic energy of motion transforms into thermal energy as the surfaces rub

4. TP: “To make connections between friction and machines.”
Efficiency and Heat
Machines with moving parts have friction, and the heat it generates makes the machine not work as well, or makes it less efficient.

5. Using Friction to Melt Steel
TP: “To make connections between friction and machines.”
Using Friction to Melt Steel

6. Quick Assessments Friction is a resistance force. True or False
TP: “To make connections between friction and machines.”
Quick Assessments
Friction is a resistance force.
True or False
Friction typically generates _______as the two surfaces rub together.
a. force
b. work
c. electricity
d. heat

7. Intellectual Engagement
TP: “To make connections between friction and machines.”
Intellectual Engagement
We put oil inside of a car to make it more slippery inside of the engine and reduce the friction.
How do you think the 1) quality of the oil and 2) how old the oil is affects how well the engine works, or efficient it is?

8. Class Activity- Motion and Friction
TP: “To make connections between friction and machines.”
Class Activity- Motion and Friction
Instructions: Using what we just learned about motion, friction, and heat… Task A- create a bubble map with efficiency in the center and details from the notes surrounding it Task B- create a tree map with efficiency at the top and the details from your notes branching downwards Task C- create a ‘cause and effect’ map of one concept we learned today. Then create a simple illustration of friction. Flexible Group- take out your portfolio and meet me in the back of the room

9. TP: “To make connections between friction and machines.”
Lesson Summary
In your tables of four, go back into your notes and consider what we have just learned today, and then…
1. Identify three (3) important concepts we learned today
2. Place those the three in order from the most important concept to least important.