In physics, mechanical energy is the sum of potential energy and kinetic energy and present in the components of a mechanical system. It is the energy associated with the motion and position of an object. The law of conservation of energy states that in an isolated system that is only subject to conservative forces, like the gravitational force, the mechanical energy is constant. If an object is moved in the opposite direction of a conservative net force, the potential energy will increase and if the speed (not the velocity) of the object is changed, the kinetic energy of the object is changed as well. In all real systems, however, non-conservative forces, like frictional forces, will be present, but often they are of negligible values and the mechanical energy's being constant can therefore be a useful approximation. In elastic collisions, the mechanical energy is conserved but in inelastic collisions, some mechanical energy is converted into heat. The equivalence between lost mechanical energy and an increase in temperature was discovered by James Prescott Joule.
Many modern devices, such as the electric motor or the steam engine, are used today to convert mechanical energy into other forms of energy, e.g. electrical energy, or to convert other forms of energy, like heat, into mechanical energy.
Other articles related to "energy, mechanical energy":
... magnet and a current-carrying coil to convert electric energy (the signal) into mechanical energy (movement that creates the sound) ... magnet, and, much like loudspeakers, they convert electric energy into mechanical energy ... A generator is the reverse it converts mechanical energy into electric energy by moving a conductor through a magnetic field ...
... an electric generator is a device that converts mechanical energy to electrical energy ... The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion ... The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators have many similarities ...
... Informally, a conservative force can be thought of as a force that conserves mechanical energy ... For non-conservative forces, the mechanical energy that is lost (not conserved) has to go somewhere else, by conservation of energy ... Usually the energy is turned into heat, for example the heat generated by friction ...
Famous quotes containing the words energy and/or mechanical:
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