Does the conservation of mass and energy mean the conservation of mass and total energy or the la

First of all, I want to correct a mistake. Someone said above that mass and energy are two aspects of materiality, just like human weight and height, not to mention the metaphor, the ontology itself in this metaphor is a wrong concept. The mistake of this proposition is "materialism", which confuses the concept of "thing".

The "matter" in the materialist phrase "the world is material" refers to all objective existences, and since they are objective existences, then they have only one attribute - objective, that is, they are not transferred by subjectivity. So mass and energy are not two attributes of objective existence, but two forms of existence that exist objectively; In other words, mass and energy belong to objective existence but do not represent the objective existence as a whole. And people's weight and height are human attributes rather than two forms of human existence, because people are not a collection, not to mention that they can both represent a person to a certain extent, which is completely different from energy and mass cannot represent objective existence.

Note: In the above text, the word mass is conceptually equivalent to "material entity", which is also in line with the meaning of m in the mass-energy equation, i.e. the mass of a certain entity).

Then let's talk about the conservation of mass and energy. Conservation of mass and energy is not equal to conservation of energy plus conservation of mass. According to the mass-energy equation, mass and energy can be converted into each other, assuming that mass becomes energy, then the total mass of the system decreases and the total energy increases, which is completely inconsistent with the law of conservation of mass and energy such as "the sum of mass and energy in a closed system remains unchanged" (in fact, I have never heard of the law of conservation of mass, probably because this "law" is a common sense that people who have not studied physics know).

Therefore, conservation of energy and conservation of mass and energy are two independent laws that should be taken into account when studying the change of energy in a closed system.

Added: Conservation of mass (is there such a statement?) I really don't know that there is this law in physics, I think it's the law of chemistry - well, chemistry and physics are one and the same after all, let's talk about this) and the conservation of energy are independent when the nuclear scale is not involved, and when the design is designed to the nuclear scale, it may be necessary to use the conservation of mass and energy as a bridge to make both be taken into account.

Also, the conservation of mass is always independent to some extent because mass has both static mass and dynamic mass. Usually the mass we talk about is static mass, not the mass at rest, but that this mass does not change with the state of motion, and the meaning of dynamic mass is the mass that only has when it is in motion (generally for energy, if the energy stops moving, it means that the energy is dissipated), so it involves the transformation of mass and energy is not conserved. Because all energy exists in the form of quanta, and quanta have dynamic mass (that is, once the quantum stops moving, the energy it contains is consumed, and this mass disappears), so even at the nuclear scale, if the mass is conserved from the perspective of both dynamic and static masses.

Conservation of mass and total amount of energy".

Einstein is conserved in mass energy, which means that mass and energy can be converted into each other, but the total amount is conserved.

e=mc^2

In a closed system, when mass is lost, the energy increases, and when the energy decreases, the mass increases.

It seems that there is no mention of "conservation of mass and energy", but there is a "mass-energy equation" or "mass-energy relationship equation", which is Einstein's theory, and it should be noted when understanding: it is not mass and energy that can be converted into each other, because the two are two different properties of matter, just like human height and weight can not be converted into each other, only the corresponding relationship - because of this, there is a so-called corresponding formula.

Both are true, but the laws have their applicability.

Conservation of mass is mainly used in chemical reactions.

Compute. Since the definition of a chemical reaction is that an atom is a particle that is minimized in a chemical change, a chemical reaction can also be seen as a recombination of atoms, and the type of element and the number of atoms remain the same before and after the reaction. Although chemical reactions are also accompanied by energy activities such as endothermic and exothermic, their influence on mass is negligible in general, and can be regarded as the same as the same as the same mass before and after the reaction, that is, the conservation of mass.

At the beginning of the 20th century, physics discovered that the mass of a high-speed moving object changes with its velocity, and that the object and the field can be converted into each other, so the mass of the field should be considered according to the mass-energy relationship. The development of the concept of mass has led to a new development of the principle of conservation of mass, and the two laws of conservation of mass and energy have been merged into one conservation law through the mass-energy relationship, that is, the law of conservation of mass and energy.

Abbreviated as the law of conservation of mass and energy).

Therefore, the conservation of mass is a law of high approximation at a lower level, and the conservation of mass and energy is a law at a higher level. Like classic physics and relativity.

The same, in a low-velocity, macroscopic, low-gravitational field.

We use classic physics, and we use relativity at high-speed, microscopic, and high-gravitational fields. Both are true.

Generally speaking, it is the conservation of mass and energy, but in many cases it also follows the conservation of mass and does not apply the conservation of mass and energy, so both statements are valid under the appropriate prerequisites.

Conservation of mass means that when an ordinary chemical reaction occurs, the total mass of reactants and products is conserved, and the conservation of mass and energy is aimed at the huge energy corresponding to the mass to be released when the mass loss occurs in a nuclear reaction, and according to Einstein's mass-energy equation, mass energy is still conserved. Note that these two statements are for different issues.

The conservation of mass and energy is correct, and in the case of nuclear reactions, mass is not conserved.

1. The idea of the law of conservation of energy was originally developed by the German physicist JMeyer proposed it in 1842 on the basis of experiments.

2. After this, the British physicist JJoule has done a lot of experiments to find the equivalent of thermal work in a variety of different ways, and the results obtained are all consistent. That is, there is a certain conversion relationship between heat and work. Later, after accurate experimental measurements, it was learned that 1 card = coke cavity god.

3. From the beginning of the 18th century to the second half of the 18th century, the manufacture and improvement of the steam engine and its wide adoption in the British ironmaking and textile industry, as well as the study of the efficiency of the heat engine and the problem of frictional heat generation in the machine, greatly promoted people's understanding of the law of energy conversion.

1. The law of conservation of energy is one of the universal basic laws of self-fiction and disagreement.

2. The general expression is: energy will neither be generated or disappear out of thin air, it will only be transformed from one form to another, or transferred from one object to another, while the total amount of energy remains the same.

3. It can also be expressed as: the change of the total energy of a system can only be equal to the amount of energy transmitted into or out of the system. The total energy is the sum of the mechanical energy, thermal energy, and any form of internal energy other than thermal energy of the system.

4. If a system is in an isolated environment, it is impossible for energy or mass to pass in or out of the Qiqi system. In this case, the law of conservation of energy is expressed as: "The total energy of an isolated system remains constant." ”

1. The idea of the law of conservation of energy and the law of slippery buffer was originally developed by the German physicist JMeyer proposed it in 1842 on the basis of experiments. After this the British physicist J

Joule has done a lot of experiments, using a variety of different methods to find the equivalent of thermal work, and found that the results obtained are consistent, that is, there is a certain conversion relationship between heat and work, and after accurate experimental measurement, it is known that 1 calorie = coul.

2. The energy conservation law (energy conservation law) letter mode, that is, the first law of thermodynamics, is a physical term, which refers to the total energy in a closed (isolated) system that remains constant. Generally speaking, the total energy is no longer just the sum of kinetic energy and potential energy, but the total amount of static and hidden energy (intrinsic energy), kinetic energy, and potential energy.

1. The idea of the law of conservation of energy was originally developed by the German physicist JMeyer proposed it in 1842 on the basis of experiments. After this was the British destroyed the Hidden State physicist J

Joule has done a lot of experiments to find the thermal work equivalent with a variety of different methods, and found that the results obtained are consistent, that is, there is a certain conversion relationship between heat and work, and it is known that the letter mode 1 card = coke is determined by accurate experiments.

2. The law of conservation of energy (energy conservation law), that is, the first law of thermodynamics, is a physical term that refers to the total energy in a closed (isolated) system that remains constant. Generally speaking, the total energy is no longer just the sum of kinetic energy and potential energy, but the total amount of rest energy (intrinsic energy), kinetic energy, and potential energy.

1. The total mass of the reactants in a chemical reaction must be equal to the total mass of the product, which is the law of conservation of mass.

2. The essence of chemical change is the recombination of atoms. Therefore, the type of atom does not change before and after the chemical change, the number does not increase or decrease, and the mass of the atom does not change. Therefore, the sum of the masses of the substances before and after the chemical reaction does not change.

The law of conservation of energy can be expressed as follows: the change in the total energy of a system can only be equal to the amount of energy transferred to or from the system. Conservation of Mechanical Energy Formula:

ek1+ep1=ek2+ep2, the formula for conservation of momentum: m1v1+m2v2+....=m1v1ˊ+m2v2ˊ+…

The law of conservation of energy is one of the universal fundamental laws of nature. The general expression is that energy is neither created nor disappeared out of thin air, it only transforms from one form to another, or from one object to another, while the total amount of energy remains the same.