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A machine is any mechanical or electrical device that transmits or modifies energy to perform or assist in the performance of tasks. It normally requires an input as a trigger, transmits the modified energy to an output, which performs the desired task.
Mechanical mechanisms and machines have been in steady use to amplify the abilities of human beings since before written records were available. The primary difference between simple tools and simple mechanisms or machines is a power source and a somewhat independent operation. The term machine generally applies to an assembly of parts operating together to perform work. Generally these devices increase intensity of applied force, changing direction of force, or changing one form of motion or energy into another.
The mechanical advantage of a machine is the ratio between the resistance or load, and the force required to overcome it, although this ratio is not entirely accurate as force is required to overcome friction, as well. To compensate for this, mechanical advantage is calculated as the ratio between the distance moved by the force applied, and the distance moved by the resistance.
Efficiency of a machine is the degree or percentage to which a machine accomplishes the work it could do without the restrictions of friction.
Modern power tools, automated machine tools, and human operated power machinery complicate this definition greatly. Machines used to transform heat or other energy into mechanical energy are known as engines.
Bearing
Driveshaft
Gear
Lever
Pulley
Screw
Spring
Wedge
Winch
Atomic clock
chronometer
Pendulum clock
Quartz clock
Archimedes screw
Eductor-jet pump
Hydraulic ram
Tuyau
Vacuum pump
Gasoline engine
Diesel engine
Four-stroke cycle
Two-stroke cycle
Wankel engine
Steam engine
Stirling engine
Gas turbine
Jet engine
Steam turbine
Water turbine
Wind generator, Windmill (Air turbine)
Calculator
Analog computer
Digital computer
Turing machine
Virus, Bacterium
Cell (biology)
Plant and animal
Human being
The mind - controversially
Category:Mechanical engineering
Category:Manufacturing
Category:Electro mechanical engineering
Category:Production and manufacturing
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