पुली का इतिहास है

चरखी के बारे में पेंटिंग पहली बार आठवीं शताब्दी ईसा पूर्व में एक असीरियन राहत में दिखाई दी थी। यह राहत एक बहुत ही सरल चरखी दिखाती है, जो केवल बल लगाने की दिशा बदल सकती है। मुख्य उद्देश्य बल के आवेदन को सुविधाजनक बनाना है और कोई यांत्रिक लाभ नहीं देता है। चीन में, चरखी उपकरण

प्राचीन काल में चरखी को चरखी कहा जाता था

प्राचीन काल में चरखी को चरखी कहा जाता था

The paintings first appeared in the portrait bricks and pottery well molds of the Han Dynasty. There are also records about pulleys in the "Mojing".

The ancient Greeks classified pulleys as simple machines. As early as 400 BC, the ancient Greeks already knew how to use double pulleys. Around 330 BC, Aristotle devoted himself to the study of the eighteenth problem in the book "Mechanical Problems" in the book "Mechanical Problems". Archimedes contributed a lot about simple machinery. Knowledge, explain in detail the kinematic theory of pulleys. It is said that Archimedes used the double pulley alone to pull a large sea ship full of cargo and passengers. In the first century AD, Alessandro's Shilo analyzed and wrote the theory about the double pulley, which proved the load and force. The ratio of is equal to the number of rope segments that bear the load, that is, the "pulley principle".

In 1608, in the book "Mathematical Collection" ("Mathematical Collection"), Dutch physicist Simon Steffen showed that the ratio of the length of the moving path between the applied force and the load of the pulley system is equal to the ratio between the applied force and the load. Inverse ratio. This is the rudimentary principle of virtual work.

In 1788, the French physicist Joseph Lagrange used the pulley principle to derive the principle of virtual work in his masterpiece "Mécanique analytique" ("Mécanique analytique"), thus unveiling the prelude to Lagrange's mechanics.