What is the difference between a fixed pulley and a movable pulley?

The distinction between a fixed pulley and a movable pulley is primarily based on their functions in terms of mechanical advantage. A fixed pulley is anchored in place and only changes the direction of the force applied; it does not contribute to reducing the amount of effort needed to lift a load. This means that when you pull down on the rope, the load is lifted upward, but the effort required remains the same as that needed to lift the load directly.

On the other hand, a movable pulley is able to move with the load, and it effectively reduces the amount of effort needed to lift that load. Specifically, with a movable pulley, the load is supported on multiple segments of the rope, allowing for less input force required to lift it. This mechanical advantage is what makes the movable pulley a more efficient tool for lifting heavy objects compared to the fixed pulley.

This understanding of the roles of fixed and movable pulleys is critical for applying the concepts of simple machines in practical situations, particularly in contexts that require lifting or moving heavy loads with minimized effort.