|Pulleys help to raise or lower the load. Pulleys have a groove that allows the rope to run through it. On one end of the rope is the effort and the other end is the load. The more pulleys you have, the easier the effort is, 2 pulleys can carry a heavier load than 1 pulley.|
*It is important for students to have the opportunity to see and use pulleys.
Examples of Pulleys: clothesline, flagpole (pulley helps raise and lower the flag)
older wells, boats that have masts, zip line, cranes, some blinds, gym equipment (to raise volleyball nets, home gyms, weight lifting equipment)
Have students describe pulleys.
Brainstorm all the things that pulleys are used for.
Brainstorm the parts of pulleys.
Discuss the difference and similarities between pulleys and wheels/axles..
Have a variety of pulleys available for students to experiment with. Invite the
custodian/janitor in to discuss how screws are used day to day and what tools are used to use the screws appropriately.
Predict if you think it’s easier to put a screw into wood? Metal? Soap? Why do you think this?
Ask why is a screw like an inclined plane? (a screw is an inclined plane wrapped into a spiral)
Simple machines are actually divided into 2 groups: Inclined Planes (Wedge, screw and ramps) Levers (Lever, wheel/axle and pulleys). Ask students wheels and axles and pulleys are like levers.
Brainstorm the exercise equipment that uses pulleys.