For a massless rope with negligible friction, tension is the same along the rope. If several vertical strands support a moving load, their tensions add. The required pulling force is load divided by supporting strands. Pulling more rope supplies the corresponding rise: rope travel equals the number of supporting strands multiplied by load travel.
Engineering and scientific investigation · Discover & try
Why can more supporting rope reduce the pull?
Reading level 3 of 5 · IndependentChange
Word help
Mechanical advantage
The ratio of output load force to input force.
Supporting strand
A rope segment pulling upward on the moving load.
Watch · Try · Explain
See how it works
The interactive activity is loading.
Massless rope, negligible friction and equal vertical tensions. Model loads and distances illustrate the force–distance trade-off.
What to look for
- Count strands attached to the moving block.
- Compare load rise with rope travel.
Explain what you noticed
For the same load and rise, what changes when an ideal system goes from two supporting strands to four?
Keep this idea: An ideal pulley trades lower force for greater rope travel; it does not create free work.
Follow the sources
- University of Colorado Boulder / TeachEngineering — Powerful Pulleys
- University of Colorado Boulder / TeachEngineering — The Power of Mechanical Advantage
Source material checked 2026-10-28. Explanations and activities by Nepedia. Source links do not imply endorsement.
You’ve reached the end of this journey
Choose another journey →