Pulleys Explained: Which Ropes to Count?

A pulley creates no force. It trades distance for force, and this section carves out exactly how. Count the rope segments that support the load and you have the ideal mechanical advantage. Pull the effort rope farther, lift the load less. Then friction enters and the real machine falls short of the ideal, so we split IMA from AMA and track where the lost energy goes. The rope-counting rule gets forced onto every setup: a fixed pulley, a single movable pulley, and a full block and tackle. By the end you read a pulley system the way you read the rest of an energy problem, with every strand accounted for. AUX — Free Physics Resources https://auxlearning.com