How to understand the application of the first law of thermodynamics to the study of the universe

1. The first law of thermodynamics: heat can be transferred from one object to another, and it can also be converted to and from mechanical energy or other energy, but in the process of conversion, the total value of energy remains the same.

2. The second law of thermodynamics: it is impossible to transfer heat from a low-temperature object to a high-temperature object without other effects, or it is impossible to take heat from a single heat source and completely convert it into useful work without other effects, or the micro-increment of entropy in an irreversible thermal process is always greater than zero.

3. The third law of thermodynamics: the entropy of a thermodynamic system tends to be fixed when the temperature approaches absolute zero.

1) The nature of the first law of thermodynamics.

For a closed system with unchanged composition, the change of internal energy can only be reflected by the exchange of heat and work between the system and the environment.

2) The nature of the second law of thermodynamics.

In an isolated system, the direction of spontaneous change is always from a more ordered state to a more disordered state, that is, from a state with a small number of microstates to a state with a large number of microstates, and from a state with a small entropy value to a state with a large entropy value.

3) The nature of the third law of thermodynamics.

At 0k, the entropy of a perfect crystal of any pure substance is zero.

In statistical physics, the third law of thermodynamics reflects the quantization of microscopic motion. In a practical sense, the third law is not like the first.

The law of one and two so clearly admonishes people to abandon the diagram of making the first and second perpetual motion machines. Rather, people are encouraged to find ways to get as close to absolute zero as possible. At present, the method of using adiabatic demagnetization has been achieved, but it can never reach 0k.

Thermal insulation, heat transfer aspects in everyday life. Such as spacecraft, submarines, etc. are all applications of the first law.

The essence of the first law of thermodynamics is a specific application of the law of conservation and transformation of energy in thermodynamics. It illustrates the possibility of the conversion of thermal energy to mechanical energy and its numerical relationship.

The First Law: The Law of Conservation of Energy.

Mass-energy equivalence as described by Einstein's special theory of relativity. Can it be understood that in an isolated system, an increase in energy is equivalent to an increase in mass, and a decrease in energy is equivalent to a decrease in mass. Mass is another representation of energy.

So why doesn't the first law make an appropriate amount of modification from the perspective of relativity?

The second law: the principle of increasing entropy in spontaneous reactions.

Since the isolated system has been observed in a small area of spontaneous entropy reduction reactions. So how do you amend the scope of application of the second law?

The Third Law: A crystal of perfect pure matter has zero entropy at absolute zero.

Does mentioning crystals here imply that the state of matter of the third law is solid. Does it mean that the Einstein-Bose condensed matter (gaseous) entropy is not zero.

The second law of thermodynamics is a fundamental law proposed by Clausius in 1850: "It is impossible to transfer heat from low to high without some kind of power expenditure or other change." This law is known as the second law of thermodynamics.

There is another formulation of the second law of thermodynamics, which is simply the principle of entropy increase, and entropy represents the degree of chaos in a system.

The first law of thermodynamics can be said to be the law of conservation of energy conversion.

For example, in order for a car to function properly, according to the first law of thermodynamics, you need to constantly add gasoline or diesel to it. And according to the second law of thermodynamics, you have to change the oil frequently. Gasoline is added to give him energy, and oil is changed to reduce his confusion, so that the entropy of the car is temporarily reduced, or to give him a negative entropy, to prolong his life, otherwise the engine will be scrapped quickly.

For people, eating is according to the first law of thermodynamics, and drinking water is according to the second law of thermodynamics. Or it is very important to eat, urine is more important, and the discharge of waste from the body must be carried out constantly, otherwise the chaos of the human body will make people scrap quickly. Of course, people eat and drink water to provide energy on the one hand, and on the other hand, to make people metabolize, metabolism is to let low entropy replace high entropy and delay aging.

Whether it is important to provide energy or slow down aging. Is the first law of thermodynamics important, or is the second law of thermodynamics important? At least all are important.

The First Law of Thermodynamics:

The internal energy increment of a thermodynamic system is equal to the sum of the heat transferred to it from the outside world and the work done to it by the outside world, and this relationship is called the first law of thermodynamics. It expresses the two ways in which life can change internal energy, and at the same time quantitatively illustrates the relationship between them.

Practical application: It is widely used in aircraft, ships, gasoline engines, diesel engines and other heat engines.

Summary: The first law of thermodynamics is the law of conservation and transformation of energy in the field of thermal phenomena, which reflects the conservation of different forms of energy in the process of transfer and transformation. 1 area.

This law has been verified by many physicists such as Meyer (Joule). It was only in the middle of the nineteenth century that it was established in the form of scientific laws on the basis of long-term production practice and a large number of scientific experiments.

Expression:The increase in the internal energy of the object is equal to the sum of the heat absorbed by the object and the work done on the object, and the expression is u=q+w.

The idea of calculus: p can be considered to have not changed when v changes minimally.

The work done at a very small change in v can be thought of as an extremely narrow rectangular area with a small change in v as the base edge and the current p as the height.

In other words, the equivalent curve can be seen as a series of right-angled polylines.

1+2 can be proved by the microelement method, da=p*dv, and the two sides are integral.

is the area of 1+2, dw=fdl=pdv, w=integral sign (pdv), and the conclusion can be known according to the geometric meaning of the definite integral.

1. The first law of thermodynamics is the law of conservation and transformation of energy in the field of thermal phenomena, which reflects the conservation of energy in different forms of silver in the process of transfer and transfer.

2. It is expressed as: the increase in the internal energy of the object is equal to the sum of the heat absorbed by the object and the work done on the object. That is, heat can be transferred from one object to another, and it can also be converted to mechanical energy or other energy, but in the process of conversion, the total value of energy remains the same.

Its generalization and essence is the famous law of conservation of energy.

The first law of thermodynamics is a very important physical principle that describes the principle of conservation of energy. The first law of thermodynamics can be applied to a variety of fields, including engineering, biology, chemistry, and more. Here are some application examples of the first law of thermodynamics.

Engineering application: Efficiency calculations of heat engines.

The first law of thermodynamics can be applied to the efficiency calculations of heat engines. A heat engine is a device that converts heat energy into mechanical energy, such as automobile engines, steam turbines, etc. According to the first law of thermodynamics, the heat input of a heat engine is equal to the mechanical work output plus the heat lost.

Therefore, the efficiency of the heat engine can be calculated by measuring the heat input and the mechanical work output.

Biological Applications: Energy Conversion of Metabolism.

The first law of thermodynamics can be applied to metabolic processes in biology. Metabolism is a chemical reaction in an organism, including the absorption and release of energy. According to the first law of thermodynamics, energy cannot be created or destroyed, it can only be transformed from one form to another.

Therefore, the energy conversion in metabolic processes must follow the principles of the first law of thermodynamics.

Answer]: CC term, the first law of thermodynamics is: heat can be converted into work, and work can also be converted into heat; Consuming a certain amount of work will produce a certain amount of heat, and when a certain amount of heat disappears, a certain amount of work will also be produced.

In the process of mutual conversion of heat and work, there is energy loss, and the perpetual motion machine requires no energy loss, that is, the perpetual motion machine is impossible to guess.

Answer] Early repentance: c

The basic content of the first law of thermodynamics is that heat can be converted into work, and work can also be converted into heat; Consuming the power of grasping and fixing will produce a certain amount of heat, and when the heat of a certain amount of land is gone, it will also produce a certain amount of work. The first law of thermodynamics is a formulation of the law of conservation and transformation of energy.

The first law of thermodynamics states that heat energy can be transferred from one object to another and can also be converted to and from mechanical energy or other energy, and the total value of the energy does not change during the transfer and conversion. Therefore, C.