A single fixed pulley makes it easier to lift a weight by allowing you to pull down on a rope rather than lift the weight up.
Note this:
- The effort you need to lift the load with the pulley is the same as the effort you need without the pulley.
- The distance you pull the rope through (the effort distance)and the distance the load moves through are the same.
If you want to move the same weight with less effort, you need to use a multiple pulley system.