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Pulley System

Last updated date: 09th Apr 2024
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Definition and Mechanism of Pulley System

You might have seen fictional characters who pull trucks with their hair and pull trains with their teeth. But you may not know that science can make you so strong. If you want to lift heavy weights, use the knowledge of science and do amazing things using a device called a pulley.

A pulley is a collection of wheels looped over a rope that is used to lift things.

A pulley system is an easy way to lift heavy objects, as compared to lifting the object barehanded. A single pulley only serves to change the direction of the applied force. When two or more forces are used in a system, then the pulley not only changes the direction of applied for but also multiplies the input force. If one fixed and one movable pulley is applied in a system, the system almost doubles the amount of force applied by a person.

Every now and then you may have encountered super-strong fictional characters who can literally do almost anything, such as pulling the trains or other such heavy vehicles all by themselves, etc. But what if someone tells you that you can be just as strong as one of your favorite characters. Well, you might be perplexed by now, but here is the interesting thing, though of course as human beings, we cannot be that super strong all by ourselves, but science can kind of make us that strong. For example, science enables us to lift heavy weights and other such things, and science does it by using a device called “Pulley”.

The Pulley system is an important part of our modern-day life because so many things have become easy for us because of the pulley system. And as a student of science, it is necessary for you to learn about the science behind the pulley system, that is to say, how the pulley system works. And to do so, you require an explanation of the pulley system in which you can understand everything, and which clears all the questions that you may have regarding the concept of the pulley system because otherwise, you are only going to be confused.

Hence to make things easy for the students Vedantu provides a Complete Explanation of the Pulley System, along with its Definition and Mechanism. And this explanation that Vedantu provides is very easy to understand. After reading it thoroughly you are not going to have any problem in understanding this wonderful mechanism called “Pulley System”. And also, Vedantu provides this explanation of the Explanation of Pulley System, along with its Definition and Mechanism completely free of cost.

Pulley System in Physics

A wheel on a shaft or an axle is designed for supportive movement. It changes the direction of the belt or the cable and also transfers power between the shaft and the belt or cable.

A pulley system that has a support frame or shell doesn't transfer power to the shaft. It is used to exert force and guide the cable in a specific direction. The shell, which is used as a support in the pulley system, basically acts as a block. It is referred to as a sheave.

The circumference of the pulley system is surrounded by flanges that contain grooves or grooves to locate the table and the belt. This system of a pulley is driven by a rope, cable, belt, or chain.

The pulley system is assembled in a way to ease the mechanical effort required to lift heavyweights.

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It is also assembled in a way such that the chain or belt will have high efficiency for transmitting power from one shaft to the other.

An Overview of the Pulley System

Pulley is nothing but a wheel built on an axle, a central shaft which is made for the rotating wheel or a gear, and it is designed to assist the movement of a cable or a belt, and it serves the purpose of transferring the power between the axle or the shaft, and the cable or the belt. Mostly Pulley has grooves, that is to say, a rather long and narrow indentation built in a given material that allows the other material to move. These grooves are built between the flanges, covering the circumference of the material, and then there is a rope, or the belt, or the chain which serves the purpose of the drive mechanism.

A Brief History of the Pulley System

The Pulley system is one of the oldest mechanisms that we are using, for instance, the evidence of the development of the pulley system can be found in many ancient civilizations, such in ancient Egypt, the use of pulley system can be found around in their twelfth dynasty, which dates back to 1991 and 1802 BCE. Even earlier than that the evidence of the Pulley System can also be found in the Mesopotamian civilization in the second millennium BCE. Also, in Egypt during the period of Roman rule, the Pulley system was used as a simple machine to lift heavyweights.

From this brief discussion, you can understand how old the pulley system is, and how important it is for us as well.

Also, if you wish to learn more about the pulley, then you may like to follow this link: Pulley - Definition, Description, Types, Formula, and Applications (

Different Types of Pulley System

There are various types of Pulley mechanisms, some of them are explained below in a brief manner:

  • Fixed Pulley: As the name suggests, this particular pulley mechanism has a wheel that cannot be moved or rotated in any direction, that is to say, it is a fixed wheel.

  • Movable Pulley: Again, as the name implies, when the wheel of the pulley can move and rotate freely then it is considered as a movable pulley.

  • Compound Pulley: When the pulley system combines the mechanism of both the system previously described, that is to say, Fixed and Movable pulley then it is the compound pulley.

Pulley Mechanism

A pulley has a unique mechanism, which makes it easier to lift heavy loads with less effort; for this reason, it has become one of the most important tools in the engineering industry. It has a wide range of applications in different industrial machines.

The work of a simple pulley is to lift a heavy load with ease by using a rope and a wheel. However, there are some other types of pulleys that have a very complex mechanism. 

The working mechanism of different types of pulley systems is given here below:

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a. Fixed Pulley

The simplest type of pulley system contains a wheel that is not free to move and rotate in any direction; this is a fixed wheel. The amount of force applied to the pulley system is the same as the weight of the pulley. This pulley system requires very little space to operate and has the simplest mechanism among all pulley systems.

b. Movable Pulley

This is also a simple pulley, but the wheel of this pulley can both move and rotate. In this pulley system, less force is required as compared to the weight of the object, to lift the object. The wheel of this pulley system translates the motion of the pulley system. This pulley system is used in almost all kinds of pulley systems and hence is very common.

c. Compound Pulley

The combination of a simple pulley and a movable pulley is called a compound pulley. It is also called a combination of the pulley. It is oriented in such a way so as to reduce the effort to less than half of the weight of the load. Thus the pulley system is mainly used by cranes to lift heavy objects of steel and concrete in construction sites.

d. Block and Tackle Pulley

The block and tackle or just tackle is a pulley system that consists of two or more pulleys attached with a rope or cable and is used to lift heavy-weight loads. In this pulley system, the pulleys are assembled in the form of blocks. The blocks are then paired in which one pulley is fixed, and the other pulley moves.

Rope Pulley System

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Pulley in oil derrick

The above-mentioned figure is a hoist using a compound pulley system that has a yielding capacity of 4. The hoist consists of one single fixed pulley and two movable pulleys (which are joined with each other) attached to the hook. One of the ends of the chain of the pulley is attached to the pulley while the other is attached to the winch.

A rope and a pulley system contain a single rope that is used to transmit force from one pulley to another, either to move or lift a load. The rope used can be a light rope or a chain that can also be used. The Renaissance scientists have included this system of the pulley in the list of simple machines.

FAQs on Pulley System

1. Give some examples of the pulley system.

Some significant pulley system examples include:

  • Multiple pulleys are used in elevators to take it up and bring it down.

  • A cargo lift system uses a pulley system to raise items to higher floors.

  • Pulley systems are used in various exercise equipment to function. 

  • Pulley is used in cranes of construction sites to lift and place heavy materials.

2. What is a block and tackle pulley system?

A block and tackle pulley works to reduce the amount of force needed to lift a heavy object like a crate to a greater extent. Standard pulley comprises a single when on an axle where a rope runs over it. A pulley here will change the direction of the force being applied to the object. 

Now, when we consider a system of the pulley, they form a block and tackle where multiple numbers of forces act to change the direction of the force. This means less force is needed for moving the object.

3. State the difference between pulley and sheave.

A pulley is among the six kinds of simple machines, whereas a sheave is a part of the pulley system that rotates and is grooved inside it.

In the case where there is no sheave in the pulley, there's a change in the force's direction to move the load, but this doesn't change the amount of force required.

So, for each sheave used in a pulley, one requires just half of the original force to shift the position of the object.

4. Does a pulley cut-weight in half?

Pulley lets you split the weight for a length of time. As you pull one meter of the rope, the weight of the object increases, which is nearly half a meter in case this is the ratio, and so appears half as heavy.

5. Why should I refer to Vedantu for the explanation of the Pulley System, along with its definition and mechanism?

There are quite many reasons for you to refer to the Explanation of Pulley System, along with its Definition and Mechanism, which Vedantu provides. One of the most important reasons is that the complete explanation of the pulley system is provided by the expert teacher of the physics subject. And they have prepared it after careful analyses of the topic, and all the points are covered by them in such a manner that it becomes extremely easy for you to understand it, and therefore the complete topic becomes easy for you. Also, the explanation that Vedantu provides for the Pulley system is completely free of cost.

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