Pulleys
by Steffan Wade
1. 3 Single fixed pulley in groups
1.1. Broom or hockey stick, 2 chairs, string, objects to test
1.1.1. Spring scale, test fore lifting object with and without pulley, uses same force
2. 4 Ask easiest way get 2 vertical brooms held by strong students can be put together
2.1. Trial pulling together with one or two students
2.1.1. Rope, leading questions, simulated compound pulley, tying rope to one pulley then wrapping around them several times
2.1.1.1. Students test, see how easy it is, explain mechanical advantage
3. 5 Create compound pulley with wire coat hanger, demonstrate then in groups
3.1. Students compare force to lift objects using fixed, movable, compound pulleys
3.1.1. Complete sheets in groups, review answers as class
3.1.1.1. Video to reinforce learning
4. 2 Cut plastic sleeves for each group before class
5. 1 Brainstorm uses of Pulleys
5.1. Curtain, flagpole, crane, clothesline, elevator
5.1.1. Practice lifting heavy object with and without pulley
5.1.1.1. Use play structure bar or hockey net, heavy bucket of sand, rope, as class
5.1.1.1.1. Easier with pulley as easier to pull down then up, use body weight
6. Create spring scales, demo then in groups
6.1. Wooden dowel, 2 elastics, tack, paperclip, plastic sleeve from margarine container, scissors, marker, tape
6.1.1. Calibrate scales, 100g for 1 Neton