In physics, mechanical energy is the sum of potential energy and kinetic energy. This energy is associated with the movement and position of an object. The principle of mechanical energy says that in an isolated system where there is only a conservative force, then the magnitude of the mechanical energy is constant.
If an object moves in the opposite direction to the conservative force, then the potential energy increases. It would be the case of a rocket, the conservative force, in this case, it would be the force of gravity. If the velocity of the object changes, then its kinetic energy also changes.
However, in all real systems, non-conservative styles such as friction forces will appear, but often their value is ignored. This makes the value of mechanical energy can be considered constant. In elastic collisions, mechanical energy will be stored, but in non-elastic collisions, part of the mechanical energy is converted into thermal energy, in the form of heat. The relationship between the loss of mechanical energy (dissipation) and the increase in temperatures was discovered by James Prescott Joule.
Many of the tools are used to convert mechanical energy from other forms of energy, such as an electric motor that converts electrical energy into mechanical energy, the electric generator converts mechanical energy into electrical energy and thermal motors or steam engines transform heat into mechanical energy.
Differences in mechanical energy with other types of energy
The grouping of energy into several types often follows the limits of the evaluation branch of the natural sciences. In this sense we could establish the following relationship of types of energy.
- Chemical energy, is a type of potential energy stored in chemical bonds.
- Nuclear energy, nuclear energy is the energy stored in interactions between particles within the atomic nucleus. Its advantageously is obtained through the reactions of nuclear fission and nuclear fusion.
- Electromagnetic energy, this type of energy comes in the form of electric charges, magnetic fields and photons. Its development is studied in the field of electromagnetism.
- Various forms of energy in quantum mechanics; for example, the energy level of an electron inside an atom.