A spontaneous process is an activity that occurs without any external energy input. For instance, a bouncing ball will fall down an inclined slope; an electrical current will flow down; water will flow downhill; hot air will condense into clouds; rock will fuse together; and water will rust. Thus, the first energy involved in a spontaneous event is high enough to overcome the second energy that follows.
Note that there is no requirement that the event be spontaneous. A chemical reaction can occur spontaneously; a change of a gas at room temperature can occur spontaneously; a change of a chemical bond in a solid can occur spontaneously; even a change of a physical location in the Earth's surface can occur spontaneously. The only thing you must keep in mind is that all the energy needed to cause the changes has to come from an outside source.
Energy comes in many forms. We can think of heat, light, sound, and electricity as forms of energy, while force, kinetic energy, potential temperature, and potential energy density are terms related to this energy. The difference between heat energy and light energy lies in the fact that heat can be turned into motion. Light, on the other hand, cannot be transformed into motion. However, when we transform light into motion, then we are dealing with electricity.
We should remember that energy is also related to the amount of information within a system. This energy is called kinetic energy and is measured by the energy per mass, which refers to the energy contained in a given mass of particles. If we consider molecules in an atomic nucleus, the kinetic energy of the atom is measured in electron volts (eV). As an example, if the atom had an eV of 100 mv, it would be considered to have a high kinetic energy. If the atom was made up of a number of atoms that were all of the same size, then its kinetic energy would be the sum of the eV of all the atoms. of the atoms. Note that the relationship between kinetic energy and eV is not a simple linear relationship: There are many variations of the kinetic energy per atom equation.
Another important aspect of energy is the time-scale involved. In an example, it might be useful to visualize a spring as a small spindled ball in a straight line. As the ball rolls down a hill, it moves up and down on its axis at a rate that varies according to the speed of the earth. This rate is called energy. For some of the energy in the ball, it will be absorbed by air; for some it is stored in the earth's gravitational field; for some, it is used to create mechanical work such as friction; and for some it is used to move the ball back to its starting point.
If we consider all these energy sources, then we can understand that the main difference between the sources of energy that occur in an object and the sources that occur in a laboratory, such as a spinning disk, is that the lab sources of energy do not vary with time. The source of an object's kinetic energy is what allows it to move, while the lab source of a laboratory energy is what causes it to stop moving. Although, energy can be described in terms of a constant, we can also look at it in terms of its speed, which can describe the speed of the objects it passes through.