Mass-energy equivalence is one of the key concepts of physics which denotes that mass and energy are the same and one. It can be represented mathematically. Einstein was not actually the founder of mass-energy equivalence but Einstein was the one who was the first to describe an accurate relationship for it in his theory of special relativity equation.

Mass energy equivalence means a small amount of mass corresponds to a large amount of energy. This special equation only represents the state of an object at rest and the energy is known as rest energy.

**Einstein Mass-Energy Equivalence Equation**

Einstein mass-energy equivalence equation is the basic formula that gives the basic relation between mass and energy. It states that under appropriate situations mass and energy are interchangeable and they are also the same. The mathematical formula of the Einstein equation is \(E=mC^{2}\).

In this equation, mass is multiplied by the speed of light as whenever energy is converted into another form of pure energy it moves at the speed of light. According to this equation, pure energy is nothing but electromagnetic radiation. Since electromagnetic radiation always moves at the speed of light hence the mass is multiplied by the speed of light in the equation. ** **

**Relation with Gravity**

Gravitational mass and inertial mass are the two types of mass. Gravitational mass is mainly the gravitational force acting on the object and also the strength of the gravitational field created by an object. The inertial mass is mainly the magnitude of acceleration when the force is applied to the object. The mass-energy equivalence topic is mainly related to inertial mass.

Newton weak equivalence theory states that the gravitational mass and inertial mass are the same. The relation between the mass-energy equivalence and gravity is as due to gravity energy, force all act on the object and results in a mass change. So due to this gravity practically we can say that gravitational and inertial mass are not the same.

**Application of Mass-Energy Equivalence**

From Einstein mass-energy equivalence relation we can understand nuclear fission and fusion reactions. We can also know from this equation that a large amount of energy is liberated during fusion reactions and nuclear fission. This equation is also useful to find out the binding energy in an atomic nucleus.

This equation also helps to find out the change in mass during a chemical reaction. In many radiotherapy treatments, the equipment is made based on this principle. To understand the gravity of the moon, star, planet we use this theory.

**FAQs about Sound Mass-Energy Equivalence**

Q.1. Explain why inertial mass and gravitational mass are not practically the same?

Answer: Mass energy equivalence is related to the inertial mass. Gravitational mass and inertial mass are not practically the same because due to gravity forces, energies all act on the object in motion and causes mass change. Hence they are practically not the same.