Feb. 2
Objectives:
• Identify lever in common household objects.
• Describe different levers for theid advantage.
• Determine E, R, etc. in different lever systems.
Bell Ringer:
Diagram a lever with:
R = 5 kg,
E = 1.5 kg,
E = 2.8 m from fulcrum.
1. Diagram
2. Calculate IMA (show calculaltions)
3. Determine distance of R from fuclrum (show calculations)
Lesson:
1) Show a normal lever; reverse R and fulcrum (to make 2nd class lever) and ask students if this is still a lever. Discuss why it is or is not.
2) Show students tweezers (or tongs) and discuss how this is a lever and where the effort, resistance, fulcrum, etc. are. Identify this as a "Class III" lever.
3) Repeat demonstration and discussion for for garlic press; identify this as a "Class III" lever.
4) Discuss uses of each type of lever (ie. what advantage does a class 3 lever give the user?)
5) See Brainpop "Levers" for description of kind of levers at: this link.
6) Distribute "Kinds of Levers" worksheet.
Assignment:
1) Complete "Kinds of Levers" worksheet. Due next class (all).