Sandbox
How do you lift a piano by hand?
More rope, less force. Build block and tackles, haul on the rope yourself, and see why sailors and builders thread rope round so many wheels.
About this sandbox
Build up to three block and tackles side by side and haul the rope yourself. Count the ropes holding the load: you pull that many times less, but pull that much more rope, and friction takes a share.
Things to try
- Compare one, two and three ropes lifting the same load.
- Lift a 250 kg piano with nine ropes.
- Add friction and see the pull you need go up.
More in Machines: Gear train. See every sandbox, or type your own equation in Free mode.