Question

How does Einstein’s equation change the law of conservation of energy ?

Answer 1

Hint:Einstein’s equation is the famous \[E = m{c^2}\]. This equation defines the energy of a moving object. The law of conservation of energy states that the energy can be neither created nor destroyed. But it can only be transformed from one form to another.Einstein proposed his equation on energy by involving the mass concept.

Complete answer:
(i) According to the law of conservation of energy, the energy can neither be created nor be destroyed. It can only be changed from one form of energy into another.
(ii) We can say many examples for this law, fans are operated by transforming electrical energy into mechanical energy. In a windmill, the mechanical energy is changed to electrical energy to produce electricity.
(iii) But in 1905 Einstein proposed his famous equation, \[E = m{c^2}\]. In this equation, he describes that the object of a particular mass is moved with the velocity of light creating energy. That energy is equal to the kinetic energy of an object.
(iv) In the bombardment of lithium by proton, the rest mass of the lithium and proton also decreases. Here the energy released in the form of alpha particles and the rest masses of the particles are also changed.
\[Li + H_1^1 \Rightarrow 2He_2^4\]
(v) By this Einstein gave a new dimension to the conservation of energy by involving the mass.

Note:The law of conservation is applicable to physical reactions, chemical reactions etc… Einstein proposed the new dimension by involving the mass of the element with the energy. The Einstein equation is useful in discovering atom bombs also. This equation helps for many radioactive experiments.