Distinction between mechanical energy, chemical energy, and internal energy

Mechanical energy. is the sum of kinetic energy and partial potential energy, and here potential energy is divided into gravitational potential energy.

and elastic potential energy. It is mass and velocity that determine kinetic energy; It is the height and mass that determine the gravitational potential energy; The elastic potential energy is determined by the stiffness coefficient and the deformation. Kinetic energy and potential energy can be converted into each other.

Mechanical energy is simply the sum of kinetic energy and potential energy. Mechanical energy is a physical quantity that represents the state and height of an object.

Chemical energy is internal energy and is an energy that is associated with thermal motion. In physics, we call the sum of the kinetic energy and molecular potential energy of all the molecules in an object moving irregularly as the internal energy of the object

energy)。All objects have internal energy. Generally speaking, the internal energy of an object represents the form of energy on the microscopic level of the object, such as the sum of the kinetic energy and potential energy of the thermal motion of the various microscopic parts (atoms, molecules, ions, etc.) inside the object, and the symbol is"j", International Authorities.

It's joules. The thermal motion energy of a thermodynamic system. Broadly speaking, internal energy is the energy determined by the internal conditions of the system.

The thermodynamic system is composed of a large number of molecules and atoms, and the energy stored in the system is the sum of the various energies of all microscopic particles, that is, the sum of the kinetic energy, potential energy, chemical energy, ionization energy, nuclear energy, and so on of the microscopic particles.

Due to the thermodynamic processes experienced by the system, the molecules, atoms, nuclei of matter.

The structure of the molecule generally does not change, that is, the intrinsic energy of the molecule (interatomic interaction energy, intraatomic energy, nuclear energy) remains unchanged and can be deducted as a constant. Therefore, the internal energy of a system usually refers to the sum of the kinetic energy of all molecules, including the kinetic energy of the translation, rotation, and vibration of the molecule (as well as the potential energy of the vibration of the atoms within the molecule), and the latter is the sum of the interaction potential energy of all possible molecular pairs. Internal energy is a function of states.

The internal energy of a real gas is a function of temperature and volume. There is no interaction between the molecules of an ideal gas, and its internal energy is only a function of temperature.

Through work and heat transfer, the system exchanges energy with the outside world, and the internal energy changes, and the relationship between them is determined by the first law of thermodynamics.

1] give. The amount of energy released when an object undergoes a chemical reaction.

In physics, we call the sum of the kinetic energy and molecular potential energy of all the molecules in an object moving irregularly as the internal energy of the object

energy)。The unit of internal energy is joule. All objects have internal energy.

Mechanical energy is the sum of kinetic energy and partial potential energy, and here potential energy is divided into gravitational potential energy and elastic potential energy.

Chemical energy is the energy released when an object undergoes a chemical reaction, which is a very hidden energy, which cannot be directly used to do work, and is only released when a chemical change occurs, turning it into heat energy or other forms of energy.

Battery. Chemical energy becomes electrical energy.

Hydroelectric generator.

Mechanical energy edges electrical energy.

Drill wood for fire. Mechanical energy becomes internal energy.

As follows:

1) Mechanical energy corresponds to mechanical motion, and internal energy corresponds to thermal motion.

2) Mechanical energy is related to the mass of the object, the speed of mechanical motion, and the position of the object, and the internal energy is related to the temperature, volume, mass, and state of matter of the object.

3) Mechanical energy includes the kinetic energy, gravitational potential energy, and elastic potential energy of the object, and the internal energy is the sum of the molecular kinetic energy and the molecular potential energy of all the molecular thermal motion in the object.

Classification of internal energy

In general physical problems (which do not involve the excited ionization of electrons, chemical reactions, and nuclear reactions), only the kinetic energy and potential energy of the molecule will change in the internal energy, and we only care about these two parts, and the sum of these two parts is defined as the internal energy. This is a simplified definition of internal energy in the narrow sense.

When it comes to the excited ionization of electrons, chemical reactions, and nuclear reactions, intrinsic energy in the narrow sense should be strictly referred to as thermodynamic energy (formerly known as thermal energy, and the concept of thermal energy is still widely used in some engineering fields) in order not to cause misunderstanding.

By definition, the difference.

Mechanical energy: The sum of the kinetic and potential energy of an object to make a mechanical motion.

Electrical energy: The work of passing an electric current through an electrical appliance.

Internal energy: the sum of the kinetic energy and the potential energy of the molecule in the object to move irregularlyLight energy: a single photon e=hr; Large-scale light energy is often calculated using the energy obtained after conversion (e.g. into heat).

Chemical energy: The energy generated by chemical change (combustion = chemical energy converted into heat energy), these energies can be directly or indirectly converted into each other.

Internal energy also refers to thermal energy [the energy of the irregular movement of a large number of particles inside an object]; Mechanical energy refers to [the combination of kinetic energy and potential energy]; Chemical energy [the interconversion of energy].

Internal energy, from a microscopic point of view, is the statistical average of the sum of the energies moving irregularly. The energy of the irregular motion of a molecule includes the kinetic energy of the molecule, the potential energy of the interaction between the molecules, and the energy of the internal motion of the molecule. Mechanical energy is the sum of kinetic energy and potential energy, and here potential energy is divided into gravitational potential energy and elastic potential energy.

Internal energy is an inherent property of objects and systems, that is, all objects or systems have internal energy, which does not depend on the existence of the outside world or whether the outside world has an impact on the system. Internal energy is a kind of extensibility (or capacity property), that is, when other factors are constant, the magnitude of internal energy is directly proportional to the quantity of matter (quantity or mass of matter).

When a certain change occurs in the system, from the original equilibrium state to another new equilibrium state, the amount of change in internal energy depends only on the state of the system before and after the change, and has nothing to do with how the change occurs (e.g., the speed of the change) and how tortuous the change is (e.g., whether it undergoes an isothermal process, isobaric process, or an arbitrary process). This property of internal energy is fundamentally different from work and heat.

Both work and heat are energy exchanged between a system and the outside world, or energy that the system absorbs or releases (to the outside world). Once the system has done work or transferred heat to the outside world, this part of the energy is no longer the energy of the system (i.e., it is no longer part of the internal energy of the system), but becomes the energy of the external object (forming part of the internal energy or kinetic energy of the external object).

The system only exists or contains internal energy (the existence of internal energy does not depend on the outside world), and there is no heat or work (without the interaction between the outside world and the system, there is no heat and work). Only when the system is under the action of the outside world (external force or temperature difference), a part of the internal energy of the system is transferred to the outside world in the form of work or heat (or vice versa). The magnitude of work and heat depends not only on the state of the system before and after the change, but also on every detail of the change.

We refer to kinetic energy, gravitational potential energy, and elastic potential energy collectively as mechanical energy. It is mass and velocity that determine kinetic energy; It is the mass and height that determine the gravitational potential energy; The elastic potential energy is determined by the stiffness coefficient and the deformation. Mechanical energy is simply the sum of kinetic energy and potential energy.

Mechanical energy is a physical quantity that represents the state and height of an object. There is a conversion between the kinetic energy and the potential energy of an object. In the process where only kinetic energy and potential energy are converted into each other, the total amount of mechanical energy remains the same, i.e., mechanical energy is conserved.

I almost forgot all about everything I knew about high school. sorry.

From a macroscopic point of view, an object has internal energy as long as it has heat. The higher the heat, the greater the internal energy. All objects have positive internal energy.

From a microscopic point of view, the internal energy is that the molecular particles of the object are constantly dripping and moving, right? The internal molecules are all dripping, and there is energy, right? These molecules are not unclear and stop dripping, and from a macroscopic point of view, they are manifested as internal energy.

Potential energy, that is, an object has a height, which is higher than other objects, and there is a height difference relative to those objects, so there is potential energy.

Mechanical energy is the sum of kinetic energy and potential energy. If it moves, there is kinetic energy. There is moving energy.

Chemical energy, it's similar to what Kukai said upstairs. Because it's not the focus in high school, it's enough to understand the concepts.

Internal energy and mechanical energy are two very important concepts in physics, and although they both belong to the category of energy, they are fundamentally different.

Internal energy refers to the energy caused by the interaction between molecules and atoms inside the object, that is, the energy caused by the thermal motion of the molecules of the object. It is a microscopic energy that is caused by the movement, vibration, and interaction of molecules. Internal energy is the sum of the energy possessed by all the molecules of a system, and its magnitude is related to temperature, pressure, type and state of matter, etc.

Mechanical energy refers to the energy possessed by an object during motion, including kinetic energy and potential energy. Kinetic energy refers to the energy that an object has due to its motion, and its magnitude is related to the mass and velocity of the object. Potential energy refers to the energy possessed by an object due to its positional relationship, and its magnitude is related to the height, shape, position, etc. of the object.

The difference between internal energy and mechanical energy is that it is different in its ** and properties. Internal energy is the energy brought about by the thermal movement of molecules, which is a microscopic energy; The mechanical energy is the energy possessed by the object in the process of motion, which is a macroscopic energy. Internal energy is the sum of the energies possessed by the molecules inside a system, while mechanical energy is the energy possessed by the motion of an object in space.

Moreover, there are different manifestations of internal energy and mechanical energy. Internal energy is usually expressed in the form of temperature, whereas mechanical energy is expressed in the form of kinetic and potential energy of an object.

In conclusion, internal energy and mechanical energy are both very important concepts in physics, but they have different properties and have different manifestations. Understanding the difference between internal energy and mechanical energy helps us to understand the concept of energy in physics more deeply.