Pulleys with One Wire


Movable Pulley

Movable pulleys can move axes, unlike fixed pulleys.
Movable pulleys have the advantage of being able to move with less force.
But, the distance that I have to move is longer than the fixed pulley.
So, there is no benefit of energy.
A movable pulley is used with a fixed pulley because it is difficult to move by itself.

Movable pulley with 1-wire

Each time a Movable pulley is added, the length of the pulling line becomes longer. Instead, the force required to move the object is reduced.
The amount of work is the product of force and workout distance, so the total work is the same.

fixed pulley

1/2 force × 2 distance

1/4 force × 4 distance

1/6 force × 6 distance

The unfolded pulley is inconvenient to use. Actually, we use the pulleys of the combined shape.
There are three lower movable pulleys in the figure below so that you can lift objects with 1/6 force.