word "energy" comes from the Greek language and has the meaning of "action", "activity".The very concept was first introduced by the British physicist T. Young in the early XIX century.The term "energy" refers to the ability to have this property to make the body work.The body is able to do so much work, the more energy it has.There are several types of it: internal, electrical, mechanical, and nuclear energy.The latter are more likely to occur in our daily lives.Man has long learned to adapt it to fit your needs, transforming into mechanical work with a variety of devices and structures.We can also transform one kind of energy to another.
As part of the mechanics (one of the branches of physics) mechanical energy - a physical quantity that characterizes the ability of a system (the body) to the performance of mechanical work.Consequently, indicative of the presence of this type of energy is the availability of a velocity of the body, having that it may perform work.
Types of mechanical energy: kinetic and potential.In each case, the kinetic energy - the scalar quantity, the sum of the kinetic energies of all material points that make up a specific system.While the potential energy of a single body (of the bodies) depends on the relative position of its (their) parts within the external force field.An indication of change of potential energy is the perfect job.
body has kinetic energy if it is in motion (otherwise it can be called the energy of motion) and potential - if it is raised above the ground on some height (this is the energy of interaction).Measured mechanical energy (and other types) in Joules (J).
To find the energy possessed by the body, you must find the work done on the translation of the body in the present state of the state of zero (when the energy of the body is equal to zero).Here are the formula, according to which can be determined by mechanical energy and its types:
- kinetic - Ek = mV2 / 2;
- potential - Ep = mgh.
Formulas: m - weight, V - velocity of its translational motion, g - acceleration of the fall, h - the height to which the body is raised above the ground.
Finding telephone system total mechanical energy is to identify the sum of its potential and kinetic components.
example of how mechanical energy can be used by man and are invented in ancient times tools (knife, spear, etc.), and the latest watches, airplanes, and other mechanisms.As the sources of the energy and the work performed by it can serve the forces of nature (wind, tides, the rivers), and the physical efforts of man or animals.
today often manual work systems (eg, the energy of the rotating shaft) to be followed by conversion of the production of electrical energy, which is used for power generators.A variety of devices (engines), capable of performing a continuous conversion to mechanical energy potential of the working body.
There is a physical law of conservation of it, according to which in the closed system of bodies, where there is no action of the forces of friction and resistance, constant is the sum of both types of it (Ek and Ep) of all of its constituent bodies.This system is ideal, but in reality, these conditions can not be achieved.