1. Teaching Point: “To calculate mechanical advantage.”
Do now Discussion: When we say you have an ‘advantage’ over someone else, what does this mean? What does it mean to ‘take advantage’ of someone? Describe a situation.

2. Formula for the Advantage
TP: “To calculate mechanical advantage.”
Formula for the Advantage
Mechanical advantage is a measure of how many times the input (effort) force is multiplied to the output (load) force. Mechanical Advantage (MA) = Output Force (FO)/ Input Force (FI) MA = FO/ FI MA has no units!

3. Mechanical Advantage Problem
TP: “To calculate mechanical advantage.”
Mechanical Advantage Problem
A system of pulleys is being used to lift up a tractor trailer for repairs in a truck repair shop. The pulley system’s input force is 150 Newtons and it lifts the truck which weighs 750 Newtons.
What is the mechanical advantage of the system of pulleys?

4. Mechanical Advantage Problem
TP: “To calculate mechanical advantage.”
Mechanical Advantage Problem
1. Write out the formula: MA = FO/ FI 2. Substitute in what you know: FO = 750 N FI = 150 N MA = 750 / 150

5. Mechanical Advantage Problem
TP: “To calculate mechanical advantage.”
Mechanical Advantage Problem
3. Write out your answer: 750/150 = 5 4. Use the correct units: Mechanical advantage has no units!

6. Quick Assessments The units for mechanical advantage is Newtons.
TP: “To calculate mechanical advantage.”
Quick Assessments
The units for mechanical advantage is Newtons.
True or False
If a person lifts an object that weighs 1000 N and puts in 1000 N in order to lift the object, what is the mechanical advantage?
a. 1 Newton
b. 1 Joule
c. 1
d. 0

7. Intellectual Engagement
TP: “To calculate mechanical advantage.”
Intellectual Engagement
Do you think a machine could have a mechanical advantage of zero? What might that look like? How would that fit into the equation for mechanical advantage? Give a situation which illustrates this possibility.

8. Class Activity- MA Calculations
TP: “To calculate mechanical advantage.”
Class Activity- MA Calculations
Instructions: Using what we just learned about MA, calculate the work for each problem below: Task A- If a pulley inputs 200 N and it outputs 400 N, calculate the mechanical advantage of the pulley. Task B- If a lever inputs 43.5 Newtons of force on a object that weighs 5x that, what is the mechanical advantage of the lever? Create one MA problem of your own Task C- create three (3) of your own ‘mechanical advantage’ problems and find the answer using the four steps Flexible Group- take out your portfolio and meet me in the back of the room

9. TP: “To calculate mechanical advantage.”
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.