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How does a pulley system work?

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According to Teach Engineering, a pulley system helps to perform work by switching directions of force and simplifying the movement of large objects. Different types of pulley systems include fixed, movable and multiple.

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Credit: Phil Whitehouse CC-BY-2.0

In a fixed pulley system, the wheel is fixed to a shaft so users can take advantage of gravity, balance an object, and help raise objects above their head. However, a fixed pulley gives no mechanical advantage, as the input force that the user provides is equal to the force of the pulley.

Movable pulleys utilize a movable wheel and differ in other respects. According to Education.com, movable pulleys have a greater mechanical advantage, meaning that the input force is less than the force of the system. Both systems also require separate amounts of rope pulls. Experts say that movable pulleys require more rope pulls by the user as the weight is lighter, but fixed pulleys require less rope pulls.

In addition, the multiple pulley is comprised of both fixed and movable pulley systems. These pulleys are easiest to lift objects with, as the mechanical advantage increases in tandem with the inclusion of more ropes, as cited by Teach Engineering. Applications of pulley systems are seen in flagpoles, modern elevators and weightlifting machines.

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Related Questions

• A:

A pulley is a simple tool that can be used for many things, such as lifting heavy objects or to change the direction of applied forces for various means. A pulley is a very simple tool that consists of a wheel on a fixed axle that has grooves for keeping a rope or wire in place. This makes pulleys useful for lifting heavy objects using applied human force.

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A pulley works by changing the direction that force must be applied to lift an object against gravity. Other, more complex, systems use multiple pulleys to reduce the amount of force that must be applied.

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A fixed pulley is stationary and doesn't move; it changes the direction of force to move an object. An example of a fixed pulley is the traditional water well where a fixed beam is suspended over the opening and the pulley is fixed to the beam to lower the bucket.