Feb. 16
Objectives:
• Each student should complete building a block and tackle pulley with correct number of assigned strings (ex. "four") and effort in correct direction (ex. "up")
• Each student should measure effort force and resistance force in a pulley, then determine IMA, AMA and efficiency.
Bell Ringer:
We have a compound pulley with three supporting strings and effort pulling down. The resistance is 250 N, the effort is 90 N, the resistance moves up 3 m:
1. Draw this pulley system
2. Determine IMA for this pulley system
3. Determine the AMA for this pulley
4. Determine the efficiency for this pulley
Lesson:
1) Students each make a 3 string pulley with effort pulling up.
• Attach 300 g mass to pulley
• Draw diagram on A4 paper.
• Determine: effort, IMA, AMA, efficiency.
• Show all measurements and ALL CALCULATIONS on your paper.
2) Repeat same exercise with effort pulling down.
3) Submit assignment before end of class.
Assignment:
1) Complete post-unit reflection and review. Bring completed reflection hand-written or printed in hard copy next period.
2) Bring reflection rubric stapled to top of your reflection with your assessment of your own work completed.
