Pulleys. Forces, motion and operation

25/08/2025

The online pulley simulations on this page will give you a better understanding of how a pulley works and how pulley systems allow heavy weights to be lifted using small forces. We will discover the most important types of pulleys and why pulleys are so important.

What is a pulley

A pulley is a mechanical device consisting of a wheel with a groove on its edge, used to change the direction and/or magnitude of force applied to a rope or cable wrapped around it. Pulleys are commonly used in pulley and cable systems to lift heavy objects or to apply forces in different directions.

Types of pulleys

There are several types of pulleys, including fixed, movable and compound pulleys.

Fixed pulleys

Fixed pulleys have a wheel that rotates on a fixed shaft

Movable pulleys

Movable pulleys have a wheel that can move along an axis.

Compound pulleys

Compound pulleys combine a fixed and a movable pulley to create an additional mechanical advantage.

The importance of pulleys in physics

Pulleys are important in physics because they can change the direction of force applied to an object and, therefore, can be used to lift heavy objects with less force. In addition, pulleys can increase the distance over which force is applied, which can also increase the resultant force.

Applications of pulleys

Pulleys are also used in engineering and construction, especially in large construction projects where heavy objects need to be lifted and moved. Cranes, for example, use pulleys to lift heavy loads effectively and safely. Pulleys are also used in heavy machinery, such as excavators and cranes, to facilitate the handling of heavy objects.

In summary, the online pulley simulations on this page will help you, in an interactive and simple way, to understand the operation of individual pulleys and pulley systems.

Explore the exciting STEM world with our free, online, simulations and accompanying companion courses! With them you’ll be able to experience and learn hands-on. Take this opportunity to immerse yourself in virtual experiences while advancing your education – awaken your scientific curiosity and discover all that the STEM world has to offer!

Pulley simulations

Pulley
Multiple
One rope
Several ropes

Introduction to pulleys

In this simulation, we will be able to check what happens when we have a system formed by two masses joined by a rope passing through a pulley. Change the masses on each side and see how they move. Can you identify and name each of the forces involved in the system?

Multiple pulleys

Multiple pulleys on a rope

The simplest type of block and tackle is one that consists of a multiple pulley system with a single cable passing through all of them. The force required to lift the mass decreases with the number of pulleys. Can you explain why? And does the energy required also decrease?

Multiple pulleys with several ropes

A somewhat more complex block and tackle is one that consists of a multiple sheave system with several cables. The force required to lift the mass decreases with the number of pulleys. Can you explain why? And does the energy required also decrease?

Equilibrium
Motion

Pulley in equilibrium

In this simulation, two different masses are connected by a rope passing through a pulley. What force must be applied to the smaller mass to keep both masses still?

Pulleys in motion

In this simulation, we can see what happens when a system consisting of two different masses connected by a rope passing through a pulley is released. Can you identify and name each of the forces involved in the system?

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