Why is e = MC2 like this?

Why is e = MC2 like this?

E = MC ^ 2, where e is the total released energy, M is the mass, and C is the speed of light
Derivation of mass energy equation
First of all, two hypotheses of special relativity should be accepted: 1. The velocity of spherical light emitted by any light source in all inertial reference frames is isotropic, and it is always C 2. The physical laws in all inertial reference frames are the same
If you walk at a speed of V and you are on a bus traveling at a speed of u, then when you walk in the same phase with the bus, your speed to the ground is U + V and U-V in the opposite direction. You spend one minute in the car and others spend one minute on the ground. This is the common sense in our minds. It is also the famous Galileo change in physics and the pillar of the whole classical mechanics, It has nothing to do with the various objects moving in it, but time passes evenly and linearly, which is the same to any observer
The above changes are in contradiction with the hypothesis of special relativity
In fact, before Einstein put forward the special theory of relativity, people observed many phenomena that were inconsistent with common sense. In order to correct the collapse of the classical physics building, physicist Lorentz proposed Lorentz transformation, but he could not explain why this phenomenon occurred, Lorentz transformation is an empirical formula based on the observed facts at that time, but it can be deduced from the pure theory of relativity
Then according to this formula, we can deduce the relationship between mass and velocity, that is, the time will slow down with the increase of velocity, the mass will increase and the length will decrease
The actual mass of an object is the sum of its static mass and its extra mass through motion
When the external force acts on a free particle with a static mass of M0, the increment of kinetic energy of the particle is DEK = f · DS for every displacement DS. If the external force and displacement are in the same direction, the above formula is DEK = FDS. If the time of the external force acting on the particle is DT, the momentum increment of the particle under the action of the impulse FDT is DP = FDT. Considering v = DS / DT, there is a division between the above two formulas, that is, the velocity expression of the particle is v = DEK / DP, That is to say, DEK = VD (MV) = V ^ 2DM + mvdv. Take the square of Einstein's formula that the mass changes with the velocity of the object to get m ^ 2 (C ^ 2-V ^ 2) = m02c ^ 2, and differential it to get: mvdv = (C ^ 2-V ^ 2) DM, and substitute it into the above formula to get DEK = C ^ 2DM, When v = 0, mass m = M0, kinetic energy EK = 0. According to the above formula, we can get ∫ ek0dek = ∫ m0m C ^ 2DM (from M0 to m) EK = MC ^ 2-m0c ^ 2
The above formula is the kinetic energy expression in the theory of relativity. Here Einstein introduced a unique idea never existed in classical mechanics. He called m0c ^ 2 the static energy of an object and MC ^ 2 the energy in motion. We use E0 and e to express them respectively: e = MC ^ 2, E0 = m0c ^ 2
Does e = MC ^ 2 violate the law of conservation of mass?
The mass energy equation does not violate the law of conservation of mass. The law of conservation of mass means that in any isolated system, no matter what changes or processes take place, the total mass always remains unchanged. In other words, chemical changes can only change the composition of matter, but can not create or destroy matter. Therefore, the law is also called the law of indestructibility of matter
The mass energy equation expresses the relationship between mass and energy, so it does not violate the law of conservation of mass