Fixed pulley

Fixed pulley features: no effort, but can change the direction of power. (Essentially an equal-arm lever).

① Definition: A pulley with a fixed shaft in the middle.

②Essence: The essence of fixed pulley is: equal arm lever

③Features: The use of fixed pulleys can not save effort but can change the direction of power.

Moving pulley

Movable pulley features: save half of the force, but can not change the direction of power, it takes distance. (The essence is that the power arm is twice the lever of the resistance arm)

① Definition: A pulley that moves with heavy objects. (Can move up and down, also can move left and right)

②Essence: The essence of the movable pulley is: the power arm is a labor-saving lever twice the resistance arm.

③Features: The use of movable pulleys can save half of the force, but it cannot change the direction of the power.

Pulley block

Pulley set: When using a pulley set, the pulley set hangs an object with several pieces of rope, and the force used to lift the object is a fraction of the weight of the object.

1. Definition: It is formed by matching several fixed pulleys and movable pulleys.

2. Features: It can save effort and change the direction of force. When using a pulley block, there are several pieces of rope hanging objects, and the force used to lift the object is a fraction of the weight of the object.