Count the supports
Count rope strands that pull upward on the load or its moving block. A fixed wheel redirects the rope without adding a supporting strand.
Pulley Workshop
Build an ideal pulley rig and discover how supporting rope strands trade less effort for a longer pull.
Grades 3–5 · Physics
Your goal
Choose 2 supporting rope strands. Lift a 80 N load exactly 1 m.
Reduced motion is on. The controls still update the scene.
1 supporting strand share the 80 N load. Your effort is 80 N. Pulling 0.0 m of rope lifts the load 0.00 m. Work in and work out are both 0.0 joules.
N
m
An ideal slow lift with a massless rope, frictionless pulleys and equal tension in every strand. Pulley weight and friction are ignored. Work is force multiplied by distance. The outgoing rope continues below the drawing.
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Learn with Pulley Workshop
Pulley Workshop helps students in grades 3–5 investigate how a simple machine changes the effort needed to lift a load. Choose one, two or four supporting rope strands, select a load weight and pull the rope in measured steps. Compare the distance pulled with the height gained, then check the matching work values. More supporting strands reduce the pulling force while increasing the rope distance. Guided goals connect this visible tradeoff with an ideal pulley system that conserves energy.
What to look for
Pull more rope
Two supporting strands need twice the rope distance for the same load rise. Four strands need four times the distance.
Compare the work
Multiply effort by rope distance and compare it with load weight multiplied by height. The ideal work values match.
For teachers and curious learners
Connect the number of supporting strands with lifting effort, rope distance and equal work. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Ideal slow lifting uses a massless rope and frictionless, weightless pulleys with equal strand tension. Real pulley rigs require extra work because of friction and moving parts.
Continue with Pulley Calculator .
Continue with Energy Tradeoffs Lab .