Screw (simple machine) advantage (the ratio of output to input force). Screws are widely used in threaded fasteners to hold objects together, and in devices such as screw tops for containers, vises, screw jacks and screw presses. Other mechanisms that use the same principle, also called screws, don't necessarily have a shaft or threads. For example, a corkscrew is a helix-shaped rod with a sharp point, and an Archimedes' screw is a water pump that uses a rotating helical chamber to move water uphill. The common principle of all screws is that a rotating helix can cause linear motion. The screw was one
Archimedes and the Cylinder I, II", "On Spirals", "On Conoids and Spheroids", "On Floating Bodies I, II", "On the Measurement of a Circle", "The Sand Reckoner". c. Boyer, Carl Benjamin "A History of Mathematics" (1991) "Arabic scholars inform us that the familiar area formula for a triangle in terms of its three sides, usually known as Heron's formula — "k" = , where "s" is the semiperimeter — was known to Archimedes several centuries before Heron lived. Arabic scholars also attribute to Archimedes the 'theorem on the broken chord' ... Archimedes is reported by the Arabs to have given several proofs