quantity that is equal to half the product of the weight of the body on the speed of this body in the square, called in physics the kinetic energy of the body, or the energy of action.Changing or volatility of the kinetic energy of the body, or driving for some time will be equal to the work that has been accomplished in a given time a certain force acting on a given body.If the work of a force along a closed path of any type will be zero, the effect of this kind is called a potential force.The work of potential forces will not depend on the trajectory of a moving body.This kind of work is determined by the initial position of the body and its end position.A reference point or zero potential energy can be chosen completely arbitrarily.The amount, which is equal to the work done by the potential power of the body to move from this position to the zero point, in physics called the potential energy of the body or energy state.
for different types of forces in physics there are various formulas for calculating the potential energy of the body or stationary.
work done by potential forces will be equal to the change of the potential energy, which should be taken in the opposite sign.
If you add kinetic and potential energy of the body, you get a value that is called the total mechanical energy of the body.In a position where a system of several bodies is conservative, for it is just the law of conservation of mechanical energy or constancy.Conservative system of bodies - is a system of bodies, which is subject only to the action of potential forces that are independent of time.
law of conservation of mechanical energy or persistence is: "During all the processes that occur in a system of bodies, its total mechanical energy always remains the same."Thus, the total mechanical energy of the whole or any body or any of the bodies remains constant, if the system is conservative bodies.
mechanical energy of any system that consists of n points, constantly interacting with each other, is the sum of the fixed potential and kinetic energy of the driving points.If the system of these points is in the external field, which are conserved or constant power, then the total mechanical energy of the system is equal to the sum of the fixed potential and kinetic energy of moving with the addition thereto of the potential energy of the system in an external field.If present in the system and non-conservative forces, while the total mechanical energy of the system can not survive, and starts to decrease, and it is the decline of non-conservative forces in the system.
If the particle system will operate only non-conservative forces, the sum of potential and kinetic energy will be saved.But it is possible interconversion of energy in the system.Potential energy can be transformed into kinetic and kinetic - potential energy.
law of conservation or constancy of the total or the whole of the mechanical energy is always invariant, that is, does not change his way of writing, even if the initial reference point of time.This is a consequence of the law of the uniformity of time.
when the system is beginning to act dissipative forces, such as the force of friction, there comes a gradual reduction or decrease in the mechanical energy of a closed system.This process is called dissipation of energy.Dissipative system - a system in which energy can be reduced over time.During dissipation complete conversion of the mechanical energy of the system to another.This is fully consistent with the universal law of energy.Thus, in nature there is no fully conservative systems.Make sure any system of bodies or material points will occur or that the power dissipation.
