Define the Law of Energy

This law for conservation of energy was proposed and researched by Émilie du Châtelet. She was a French natural philosopher and a mathematician. 

As an example of the execution of the law, when a dynamite explodes causing an explosion, it converts chemical energy stored inside it into kinetic energy. There are many types of energy being released from the change of chemical energy, like potential energy, kinetic energy, sound energy and heat energy. We can combine all these energies together to find the exact amount of chemical energy which changed forms.

Energy

Energy can be defined as a quantitative and physical system which is necessary to do a certain work by the body or to heat it. Energy is a conserved quantity as it abides by the law of conservation of energy . The SI unit of energy is joule . The energy of 1 joule means the energy required or transferred to an object by moving the body for a displacement of 1 metre and a force of 1 newton. 

Define conservation of energy

Apart from the laws of conservation of energy , the definition of conservation of energy means that the energy would not be destroyed anyhow but be conserved by changing its own form in other forms of energy. Eg:- kinetic energy to potential energy. 

The law of conservation of energy (Formula) 

The formula of conservation of  energy is :-

K1 + U1 = K2 + U2 

Here K1 is the initial kinetic energy and U1 is the initial potential energy. K2 is the final kinetic energy and U2 is the final initial potential energy. 

The main aim of this formula is that at the beginning the sum of the kinetic energy and potential energy is equal to the sum of the final kinetic and potential energies. Since there is no change in their sum , it symbolizes that even after this the energy just changed from one form to another without even a bit getting destroyed. 

Relativity theory

It is a theory proposed by Albert Einstein in 1905 and was published in 1915 . The theory deals with two theories which are interconnected, special relativity theory and the general relativity theory by Albert Einstein himself. 

General relativity is about the gravitational laws related with other forces of nature. Whereas , special relativity deals with the phenomenon which takes place in the absence of gravity. 

This theory also highlights the relationship of mass and energy using the rule known as mass-energy equivalence.

E = mc2

E denotes the energy, m symbolizes the mass of the object and c is the speed of light. 

The formula made by Einstein simply states that energy and mass of an object are also interchangeable as they are just stored in different forms but are the same from the foundation. Only in the right conditions or when multiplied by the square of the speed of light ( c2) . 

Conclusion

The theory/law of conservation of energy has been proven and tested by scientists many times now . There are many supporting theories like the relativity theory, laws of thermodynamics, quantum theory and the noether theorem. The relativity theory is by far the most famous and most studied theory among these theories.