The Single Fixed Pulley System
Do you have a heavy load? If so, things are looking up. Experiment with a single fixed pulley system and see how a pulley can make a load seem lighter.
Problem: What is a fixed pulley? What does it do?
- Ribbon spool
- 4 feet of thin rope or string
- Duct tape
- Small plastic doll
- To create your pulley, duct tape the dowel to a table, the side of some stairs, or something else that’s relatively high off the ground. Make sure the dowel sticks out over the edge of whatever surface you’re using.
- Place the empty spool of ribbon onto the dowel. This acts as your pulley.
- Now, cut a piece of thin rope or string and drape it over your spool so that equal lengths of string hang over either side of the pulley. Move it back and forth to make sure it won’t fall off.
- Find something to lift. If you have a toy that would like a ride up into the air, attach it to one length of string using the tape. Now, gently pull down on the other length of string. Observe what happens.
A fixed pulley changes the direction of the force you exert by pulling, so you can pull down to move an object up.
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