Pulley System Simulator
Pull the rope, see how more rope strands cut the force you need but lengthen the pull.
Choose a pulley set-up or set the number of supporting ropes yourself. Drag the rope end down to lift the load. See how many times smaller the effort is, how much further you must pull, and how friction and your own strength change the result. Work in always equals work out plus wasted heat.
What the Pulley System Simulator shows
Pull the rope, see how more rope strands cut the force you need but lengthen the pull. Free, no signup, runs in your browser. Built for engineering, the pulley system simulator runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Fixed and movable pulleys with 1 to 4 supporting ropes. You lift a load and compare the pull force with the distance of rope you must haul.
How to use the Pulley System Simulator
In the Pulley System Simulator, use the controls to change Set-up, Number of supporting ropes, Load mass, Friction per pulley wheel, Your strength (max pull). The simulation reacts instantly.
In the Pulley System Simulator, pick an option such as 1 fixed pulley, Movable pulley (2 ropes), 3 ropes, 4 ropes to switch modes or load an example.
In the Pulley System Simulator, press "Lower the load", "Raise fully", "Reset" to start, reset or change what is happening.
Start with this experiment: Set 4 strands, then drag the rope handle down and read the effort force. Drag any glowing handle, object or slider with your mouse or finger and the Pulley System Simulator responds in real time.
Change one setting at a time and watch which readout moves, then compare it with this idea: With n supporting strands the ideal effort force is load ÷ n.
Things to try
Set 4 strands, then drag the rope handle down and read the effort force.
Compare the distance you pull with how far the load rises.
Add friction and see the efficiency drop.
Raise the load to its limit to see the maximum lift.
The science behind it
With n supporting strands the ideal effort force is load ÷ n.
You pull n times as much rope as the load rises, so the work stays the same.
Friction lowers the efficiency, so the real effort is a bit bigger than ideal.
A worked example with real numbers
W = 60 × 9.81 = 588.6 N Ideal effort = 588.6 / 4 = 147 N To lift the load 1 m you pull 4 m of rope. Friction in each wheel raises the real effort above 147 N.
Tips and common mistakes
Tips
- Compare 1, 2, 3 and 4 ropes: effort drops while the rope length you pull grows.
- Turn friction up to see why real pulleys have efficiency below 100%.
- Watch the work in versus work out; ideal work is equal.
Common mistakes
- A fixed pulley only changes direction; it gives MA = 1.
- Only ropes pulling the movable block up count toward n.
- You never get free energy: less force means more distance.
Where this is used
Pulleys lift loads on cranes, sailboats, elevators and construction sites. The block and tackle multiplies force so people can move heavy loads.
Who is this simulation for?
Engineering and technology students, makers, robotics clubs and teachers of design and technology. A good first experiment in the Pulley System Simulator: Set 4 strands, then drag the rope handle down and read the effort force. The key relation to keep an eye on: Ideal mechanical advantage MA = n (number of supporting rope segments). Effort = W / n, rope pulled = n × load rise.
For teachers: project the Pulley System Simulator on the board, let students predict the result, then run it together and test this: Compare the distance you pull with how far the load rises. For students: change one thing at a time and write down what changes.
Frequently asked questions
What is mechanical advantage?
The factor by which a machine multiplies your force. For an ideal pulley system it equals the number of rope strands supporting the load.
Do pulleys reduce the work needed?
No. They reduce the force but you pull a longer distance, so the work (force × distance) is the same in an ideal system.
Is the Pulley System Simulator free to use?
Yes. The Pulley System Simulator is free, needs no signup or download and runs in your web browser. It is part of the Engineering group of AZRS simulations.
Does the Pulley System Simulator work on a phone or tablet?
Yes. The Pulley System Simulator takes touch input as well as mouse input, so you can use its 5 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
