E=mc?.

The mass-energy formula is the mass-energy equation. Einstein's famous mass-energy equation E=mc?, E represents energy, m represents mass, and c represents the speed of light constant.

In classical mechanics, mass and energy are independent and have no relationship with each other, but in relativistic mechanics, energy and mass are interchangeable.

This is true regardless of whether the object is moving or stationary: for a stationary object, m is the inherent mass or rest mass of the object, so it must have huge energy, and the mass of the moving object increases with the speed. Therefore the energy also increases (equivalent to an increase in kinetic energy). Since the speed of photons is the speed of light, it is impossible for photons to have rest mass, and the speed of objects or particles with non-zero rest mass cannot reach the speed of light. When the speed approaches the speed of light, its energy approaches infinity.

E=mc?Expression form:

1. E0=M0C?.

M0 in the above formula is the rest mass of the object, and E0 is the rest energy of the object. The mass-energy equation described in middle school physics textbooks has the same meaning as this expression, and is usually abbreviated as E=mc?.

2. Ev=MvC?.

Mv is the mass that increases as the motion speed increases. Ev is the energy of an object in motion, which is the sum of the object's rest energy and kinetic energy.

3. ΔE=ΔMvC?.

Δ in the above formula is usually the change in the object’s rest mass, that is, mass loss. ΔE is the change in the object’s rest energy. In fact, this expression is the differential form of form 1.