Archimedes discovered the law of lever and what law?

Archimedes discovered the lever theorem and buoyancy theorem. Introduction to the principle of buoyancy: the buoyancy obtained by an object in a liquid is equal to the weight of the liquid it discharges, that is, F=G (where f is the buoyancy of the object and g is the gravity of the object when it discharges the liquid).

Lever principle: A system that satisfies the following three points is basically a lever: fulcrum, force point and force point. The lever principle is also called "lever balance condition": in order to balance the lever, the two moments (product of force and arm) acting on the lever must be equal. Namely: power× power arm = resistance× resistance arm.

Other achievements in extending data characters:

Archimedes' study of machinery originated from his study in Alexandria. One day, after a long drought, Archimedes was walking along the Nile. He saw that it was quite difficult for farmers to carry water to irrigate their land. He thought about it, and invented a tool for rotating and absorbing water in the water pipe through spiral action, which was later called "Archimedes spiral water lifter".

Archimedes invented a cross goniometer for astronomical measurement and made an instrument for measuring the angle between the sun and the earth. Archimedes also made a planetarium by hydraulic power, with the sun, moon, stars and five planets on the sphere. According to records, this planetarium not only runs accurately, but also can predict when there will be a lunar eclipse or a solar eclipse.

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