How to understand energy in physics, and what exactly is energy in physics

Energy and force have nothing to do with each other. Energy is an abstract concept"force"It can be understood as a manifestation of one of the energies - "mechanical energy". In addition, there is internal energy (expressed in terms of temperature), chemical energy, nuclear energy, and various kinds of energy.

The one you are talking about is only part of the law of conservation of energy - "conservation of mechanical energy", which is premised, that is, in the absence of heat exchange, an object moves vertically downward, and its gravitational potential energy decreases, which will inevitably lead to an increase in its kinetic energy (i.e., faster and faster).

It is not a ratio, it can be verified by experiments: potential energy change + kinetic energy change = 0 As for the entire energy conservation law, it is believed that energy is conserved in the universe, for example, solar radiation energy is converted into chemical energy by plants, stored in the body, buried in the ground, turned into coal, and after combustion, chemical energy becomes internal energy, so that water evaporates, water vapor drives the steam turbine, and internal energy becomes mechanical energy ......In this whole process, energy is conserved, and energy is not generated for no reason, nor does it disappear for no reason.

Do you understand? Didn't understand to continue the discussion.

Energy and force have nothing to do with it.

It can be converted and can be understood as a ratio.

However, in an ideal case, the odds are 1

The causes of the two are unrelated, but it does not mean that the results are unrelated.

If an object can do work externally, or that the object has the ability to do external work, we say that it has a certain amount of energy. The greater the ability to do work, the greater the energy.

Energy exists in various forms, such as, kinetic energy, gravitational potential energy, elastic potential energy, electric potential energy, etc., as well as chemical energy, thermal energy, etc.

The conservation of energy is a fundamental law of nature, energy can only be transferred from one object to another, or from one form to another, and cannot be destroyed or created out of thin air.

The law of conservation of mechanical energy is a subset or special case of conservation of energy. The object you threw and fell above and the object you said above, the object only has gravity to do work during the motion, so the mechanical energy is conserved, in this way, the sum of the kinetic energy and gravitational potential energy of the object remains the same, but the gravitational potential energy is converted into kinetic energy during the falling process, and the kinetic energy is gradually converted into gravitational potential energy during the ascending process, which is the transformation of energy from one form to another.

1. Energy in physics refers to the description of the motion of all macroscopic and microscopic matter.

2. Energy is the quantitative transformation of the movement of matter, referred to as "energy". Everything in the world is in constant motion, and among all the attributes of matter, motion is the most basic attribute, and all other attributes are the specific manifestations of the attributes of motion.

3. In physics, energy is an indirectly observed physical quantity. It is often seen as the ability of one physical system to do work on other physical systems. Since work is defined as a force acting over a distance, energy is always equated with the ability to block the fundamental forces of nature along a certain length.

4. The total energy contained in an object is based on its mass, and energy, like mass, generally does not disappear out of nothing or for no reason. Energy, like mass, is a scalar quantity. In the International System of Units, the unit of energy is joules.

There are three definitions:

1. A measure of the motion of matter. Corresponding to the various forms of motion of matter, there are also various forms of energy, which can be converted into each other, but the total amount remains the same. Energy in thermodynamics mainly refers to thermal energy and mechanical energy converted from thermal energy.

Disciplines: first-level discipline of electric power, second-level discipline of general theory;

2. The foundation of the living system and the power of the ecosystem, and the energy flow and transformation that exists in all life activities. Disciplines: first-level discipline of ecology, second-level discipline of ecosystem ecology;

3. Measure the physical quantity of work done by an object. Disciplines: first-level discipline of resource science and technology, second-level discipline of energy and resource science.

Energy can be understood as the ability of an object to do work.

The greater the ability to do work, the more work can be done.

The energy of an object is not necessarily doing work on the outside.

The object is doing work externally and must have energy.

For example, nuclear energy - atomic bomb - no, it cannot be said that it has no energy; ** When the energy is released, the damage caused is great!

Energy is a measure of how much the spatial and temporal distribution of mass is likely to change, and is used to characterize the ability of a physical system to do work.

Modern physics has clarified the quantitative relationship between mass and energy, that is, Einstein's mass-energy relation: e=mc2.

The unit of energy is the same as the unit of work and is joules (j) in the International System of Units. In the fields of atomic physics, nuclear physics, particle physics, etc., electron volts (EV) are commonly used as a unit, 1 electron volt = , 18 10 19 joules. In the field of physics, Erg is also used as a unit of energy, 1 Erg = 10 7 joules.

Energy exists in many different forms; According to the classification of different forms of motion of matter, energy can be divided into mechanical energy, chemical energy, thermal energy, electrical energy, radiation energy, nuclear energy, light energy, tidal energy, etc. These different forms of energy can be converted into each other through physical effects or chemical reactions. Various fields also possess energy.

Heat refers to the energy transferred between the thermal system and the outside world by the temperature difference. Heat is a process quantity, so heat can only be said to be "absorbed" and "released". It is not possible to say "contains" "has".

And this transfer process is called heat exchange or heat transfer. The unit of heat is joules (j). All life activities of the human body require energy, such as the synthesis reaction of material metabolism, muscle contraction, gland secretion, and so on.

And this energy is mainly in food. The nutrients contained in animal and plant foods can be divided into five main groups: carbohydrates, lipids, proteins, minerals and vitamins, and water as the six main groups.

Carbohydrates, fats, and proteins are oxidized in the body to release energy. The three are collectively referred to as "energy nutrients" or "calorific substances".

Law of Conservation of Energy:

Energy must obey the law of conservation of energy. According to this law, energy can only change from one form to another and cannot be created or destroyed in a vacuum. Conservation of energy is a mathematical conclusion drawn from the translational symmetry of time (translational invariance).

The law of conservation of mass and energy.

The law of conservation of mass and energy states that the sum of the relativistic kinetic and static energies of all particles remains constant during the interaction in an isolated system. The law of conservation of mass and energy is a special form of the law of conservation of energy.

Laws of Thermals: The Zeroth Law of Thermodynamics: If each of the two thermal systems is in thermal equilibrium with the third thermal system, they are also in thermal equilibrium with each other.

The first law of thermodynamics: A system includes the transfer and conversion of energy in any process, and the value of its total energy remains constant. That is, conservation of energy.

The second law of thermodynamics: Heat can only be transferred spontaneously from hot objects to low temperatures. The direction of heat transfer is opposite to that of the temperature gradient. This is Clausius's formulation, also known as the entropy increase principle, which shows that the world will become more and more disorderly, more and more chaotic.

The third law of thermodynamics: absolute zero is impossible to reach.