What Are The Classifications Of Pulleys?

There are two types of pulleys: fixed pulleys and movable pulleys, which are combined into a pulley set, which can save labor and change the direction of force.
fixed pulley
Definition: A pulley that is fixed in one position and rotates without moving is called a fixed pulley.
The function of the fixed pulley is to change the direction of the force
The essence of the fixed pulley is an equal-arm lever. The power arm L1 and the resistance arm L2 are both equal to the radius of the pulley. According to the lever balance condition, it can also be concluded that the fixed pulley does not save effort and distance.
moving pulley
The movable pulley is essentially a lever with twice the power arm as the resistance arm, saving 1/2 the effort and spending 1x the distance.
(Note: The premise of the above sentence is that the pulling force direction is vertical to save 1/2 of the force. If it is in a diagonal pulling state, the pulling force is more than 1/2 of the force saved, and the larger the angle, the more laborious it is.)
pulley block
Pulley block: A pulley block composed of a fixed pulley and a movable pulley, which saves effort and can change the direction of force.
The pulley block uses several lengths of rope to hang an object. The force used to lift the object is a fraction of the total weight. The free end of the rope that goes around the movable pulley is counted as one section, while the one that goes around the fixed pulley is not counted.
Although using a pulley block saves effort, it consumes distance. The distance moved by power is greater than the distance moved by the heavy object.