Lever

Lever
Levers can be used to exert a large force over a small distance at one end by exerting only a small force over a greater distance at the other.
Classification	Simple machine
Industry	Construction
Weight	Mass times gravitational acceleration
Fuel source	potential and kinetic energy {mechanical energy }
Components	fulcrum or pivot, load and effort

A lever (/ˈliːvər/ or US /ˈlɛvər/) is a machine consisting of a beam or rigid rod pivoted at a fixed hinge, or . A lever is a rigid body capable of rotating on a point on itself. On the basis of the location of fulcrum, load and effort, the lever is divided into three types. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever.

The word "lever" entered English about 1300 from Old French, in which the word was levier. This sprang from the stem of the verb lever, meaning "to raise". The verb, in turn, goes back to the Latin levare, itself from the adjective levis, meaning "light" (as in "not heavy"). The word's primary origin is the Proto-Indo-European (PIE) stem legwh-, meaning "light", "easy" or "nimble", among other things. The PIE stem also gave rise to the English word "light".

The earliest remaining writings regarding levers date from the 3rd century BC and were provided by Archimedes. 'Give me a place to stand, and I shall move the Earth with it' is a remark of Archimedes who formally stated the correct mathematical principle of levers (quoted by Pappus of Alexandria). The distance required to do this might be exemplified in astronomical terms as the approximate distance to the Circinus galaxy (roughly 3.6 times the distance to the Andromeda Galaxy) - about 9 million light years.