January 2020
Beginner to intermediate
232 pages
11h 26m
English

In this chapter we discuss a wonderfully useful simple machine: the pulley. Archimedes (who we already mentioned in the levers chapter) is credited with developing the first fully-realized and documented compound pulley system. Plutarch, a Greek historian, wrote that Archimedes moved a naval ship at the request of King Hieron of Syracuse (in Sicily) by setting up a system of pulleys and then, while seated “some distance away,” moved the ship “as smoothly and evenly as if she had been in the sea.”
In its typical form, a pulley is a grooved wheel on a supported axle, around which the wheel rotates. Figure shows ...