Kinetic potential law of conservation of energy. Energy
Energy- a measure of the movement of matter in all its forms. The main property of all types of energy is interconvertibility. The amount of energy that a body possesses is determined by the maximum work that the body can do, having used up its energy completely. Energy is numerically equal to the maximum work that the body can do, and is measured in the same units as the work. During the transition of energy from one type to another, it is necessary to calculate the energy of the body or system before and after the transition and take their difference. This difference is called work:
Thus, the physical quantity characterizing the ability of a body to perform work is called energy.
The mechanical energy of a body can be due either to the movement of the body at a certain speed, or to the presence of the body in a potential field of forces.
Kinetic energy.
The energy possessed by a body due to its motion is called kinetic. The work done on the body is equal to the increment of its kinetic energy.
Let's find this work for the case when the resultant of all forces applied to the body is equal to .
The work done by the body due to kinetic energy is equal to the loss of this energy.
If other bodies act on the body at each point in space, then the body is said to be in a field of forces or a force field.
If the lines of action of all these forces pass through one point - the force center of the field - and the magnitude of the force depends only on the distance to this center, then such forces are called central, and the field of such forces is called central (gravitational, electric field of a point charge).
The field of forces constant in time is called stationary.
A field in which the lines of action of forces are parallel straight lines located at the same distance from each other is homogeneous.
All forces in mechanics are divided into conservative and non-conservative (or dissipative).
Forces whose work does not depend on the shape of the trajectory, but is determined only by the initial and final position of the body in space, are called conservative.
The work of conservative forces along a closed path is zero. All central forces are conservative. The forces of elastic deformation are also conservative forces. If only conservative forces act in the field, the field is called potential (gravitational fields).
Forces whose work depends on the shape of the path are called non-conservative (friction forces).
Potential energy is the energy possessed by bodies or body parts due to their relative position.
The concept of potential energy is introduced as follows. If the body is in a potential field of forces (for example, in the gravitational field of the Earth), each point of the field can be associated with some function (called potential energy) so that the work A 12, performed over the body by the forces of the field when it moves from an arbitrary position 1 to another arbitrary position 2, was equal to the decrease of this function on the path 1®2:
,
where and are the values of the potential energy of the system in positions 1 and 2.
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In each specific problem, it is agreed to consider the potential energy of a certain position of the body equal to zero, and take the energy of other positions relative to the zero level. The specific form of the function depends on the nature of the force field and the choice of the zero level. Since the zero level is chosen arbitrarily, it can have negative values. For example, if we take as zero the potential energy of a body located on the surface of the Earth, then in the field of gravity forces near the earth's surface, the potential energy of a body of mass m, raised to a height h above the surface, is (Fig. 5).
where is the displacement of the body under the action of gravity;
The potential energy of the same body lying at the bottom of a well with depth H is equal to
In the considered example, it was about the potential energy of the Earth-body system.
Potential energy of gravity - the energy of a system of bodies (particles) due to their mutual gravitational attraction.
For two gravitating point bodies with masses m 1 and m 2, the potential energy of gravity is:
,
where \u003d 6.67 10 -11 - gravitational constant,
r is the distance between the centers of mass of the bodies.
The expression for the potential energy of gravity is obtained from Newton's law of gravity, provided that for infinitely distant bodies the gravitational energy is 0. The expression for the gravitational force is:
On the other hand, according to the definition of potential energy:
Then .
Potential energy can be possessed not only by a system of interacting bodies, but by a single body. In this case, the potential energy depends on the relative position of the body parts.
Let us express the potential energy of an elastically deformed body.
The potential energy of elastic deformation, if we assume that the potential energy of an undeformed body is zero;
Where k- coefficient of elasticity, x- deformation of the body.
In the general case, a body can simultaneously possess both kinetic and potential energies. The sum of these energies is called full mechanical energy body: .
The total mechanical energy of a system is equal to the sum of its kinetic and potential energies. The total energy of the system is equal to the sum of all types of energy that the system possesses.
The law of conservation of energy is the result of a generalization of many experimental data. The idea of this law belongs to Lomonosov, who stated the law of conservation of matter and motion, and the quantitative formulation was given by the German physician Mayer and the naturalist Helmholtz.
Law of conservation of mechanical energy: in the field of only conservative forces, the total mechanical energy remains constant in an isolated system of bodies. The presence of dissipative forces (friction forces) leads to dissipation (scattering) of energy, i.e. converting it into other types of energy and violating the law of conservation of mechanical energy.
The law of conservation and transformation of total energy: the total energy of an isolated system is a constant value.
Energy never disappears and does not appear again, but only changes from one form to another in equivalent quantities. This is the physical essence of the law of conservation and transformation of energy: the indestructibility of matter and its motion.
An example of the law of conservation of energy:
In the process of falling, potential energy is converted into kinetic energy, and the total energy, equal to mgH, remains constant.
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Define a job? What letter stands for? In what units is it measured? Under what conditions is the work done by a force positive? negative? equal to zero? What forces are called potential? Give examples? What is the work done by gravity? Force of elasticity? Define power. In what units is power measured? TASKS FOR ORAL SURVEY:
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TASKS FOR REPETITION OF THE STUDYED MATERIAL: 1. A car with a mass of 1000 kg, moving uniformly accelerated from a state of rest, drives off 200 m in 10 s. Determine the work of the traction force if the coefficient of friction is 0.05. Answer: 900 kJ 2. When plowing, the tractor overcomes the resistance force of 8 kN, developing a power of 40 kW. How fast is the tractor moving? Answer: 5 m / s 3. The body moves along the OX axis under the action of a force, the dependence of the projection of which on the coordinate is shown in the figure. What is the work done by the force on the 4m path?
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Subject: Energy. Kinetic energy. Potential energy. The law of conservation of mechanical energy. Application of conservation laws Lesson objectives: Educational: get acquainted with the concept of energy; to study two types of mechanical energy - potential and kinetic; consider the law of conservation of energy; develop problem solving skills. Developing: promote the development of speech, teach to analyze, compare, promote the development of memory, logical thinking. Educational: assistance in self-actualization and self-realization in educational process and the future of professional activity LECTURE OUTLINE 1.Mechanical energy 2.Kinetic energy 3.Potential energy 4.The law of conservation of energy (video demonstration) 5.Application of the law of conservation of energy
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1. Mechanical energy Mechanical work (A) is a physical quantity equal to the product of the modulus of the acting force and the path traveled by the body under the action of the force and the cosine of the angle between them A \u003d F S cosα The unit of work in the SI system is J (Joule ) 1J=1N m.
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Work is done when a body moves under the action of a force. Let's look at a few examples.
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Bodies that can do work are said to have energy. Energy is a physical quantity that characterizes the ability of bodies to do work. The unit of energy in the SI system is (J). Indicated by the letter (E)
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2. Kinetic energy How does the energy of a body depend on its speed? To do this, consider the motion of a body of some mass m under the action of a constant force (it can be one force or the resultant of several forces) directed along the displacement.
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This force does work A=F S According to Newton's second law F=m a Body acceleration
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Then, The resulting formula connects the work of the resulting force acting on the body with a change in the value of the Kinetic energy of the body - this is the energy of motion. The kinetic energy of a body is a scalar quantity, which depends on the modulus of the body's velocity, but does not depend on its direction. Then, the work of the resultant of all forces acting on the body is equal to the change in the kinetic energy of the body.
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This statement is called the kinetic energy theorem. It is valid regardless of what forces act on the body: the force of elasticity, the force of friction or the force of gravity. And the work necessary to disperse the bullet is done by the pressure force of the powder gases. So, for example, when throwing a spear, the work is done by the muscular strength of a person.
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So, for example, the kinetic energy of a boy at rest relative to the boat is equal to zero in the frame of reference associated with the boat, and is different from zero in the frame of reference associated with the shore.
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3. Potential energy The second type of mechanical energy is the potential energy of the body. The term "potential energy" was coined in the 19th century by the Scottish engineer and physicist William John Rankine. Rankin, William John Potential energy is the energy of a system, determined by the mutual arrangement of bodies (or body parts relative to each other) and the nature of the forces of interaction between them
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The value equal to the product of the body mass, free fall acceleration and body height above zero level is called the potential energy of the body in the gravitational field. The work of gravity is equal to the decrease in the potential energy of the body in the Earth's gravitational field.
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When the value of deformation changes, the elastic force performs work, which depends on the elongation of the spring in the initial and final positions. On the right side of the equation, there is a change in the value with a minus sign. Therefore, as in the case of gravity, the value Thus, the work of the elastic force is equal to the change in the potential energy of an elastically deformed body, taken with the opposite sign.
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4. Law of Conservation of Energy Bodies can simultaneously possess both kinetic and potential energy. So, the sum of the kinetic and potential energy of the body is called the total mechanical energy of the body or simply mechanical energy. Is it possible to change the mechanical energy of the system and, if so, how?
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Consider a closed system "cube - inclined plane - Earth" According to the kinetic energy theorem, the change in the kinetic energy of the cube is equal to the work of all forces acting on the body.
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Then we get that the increase in the kinetic energy of the cube occurs due to the decrease in its potential energy. Therefore, the sum of changes in the kinetic and potential energies of the body is zero. And this means that the total mechanical energy of a closed system of bodies interacting with gravitational forces remains constant. (The same result can be obtained under the action of the elastic force.) This statement is the law of conservation of energy in mechanics.
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One of the consequences of the law of conservation and transformation of energy is the assertion that it is impossible to create a "perpetual motion machine" - a machine that could do work indefinitely without consuming energy.
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TASKS FOR CONSOLIDATION OF THE GAINED KNOWLEDGE A bullet weighing 20 g is fired at an angle of 600 to the horizon with an initial speed of 600 m/s. Determine the kinetic energy of the bullet at the moment of its highest rise. The spring holds the door. In order to slightly open the door, stretching the spring by 3 cm, you need to apply a force equal to 60 N. In order to open the door, you need to stretch the spring by 8 cm. What work must be done to open the closed door? A stone is thrown from the surface of the Earth vertically upwards with a speed of 10 m/s. At what height will the kinetic energy of the stone decrease by 5 times compared to the initial kinetic energy
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Horizontally. 1. The unit of energy in the SI system. 4. The body is a classic example for describing jet propulsion. 5. A physical quantity equal to the work done per unit of time. 7. Property of the system necessary for the conservation of momentum or energy. 9. The meaning of the word "impulse" in Latin. 12. The general property of a number of quantities, the essence of which is the invariance of the quantity in time in a closed system. 13. The unit of power in the SI system. Vertically. 2. The state of the system in which the potential energy is zero is zero ... . 3. A common property for potential and kinetic energy, expressing their dependence on the choice of reference body. 4. A physical quantity equal to the product of the projection of the force on the direction of movement and the module of movement. 6. A physical quantity equal to the product of a body's mass and its speed. 8. A quantity that coincides in direction with the momentum of the body. 9. The statement, the essence of which is that the change in kinetic energy is equal to the work of the resultant of all forces applied to the body. 10. One of the quantities on which the change in the momentum of the body depends. 11. The value characterizing the ability of the body (system) to perform work.
The muscles that move the links of the body perform mechanical work.
Work in a certain direction is the product of a force (F) acting in the direction of movement of the body on the path it has traveled (S): A \u003d F * S.
Doing work requires energy. Therefore, when work is done, the energy in the system decreases. Since in order for work to be done, a supply of energy is needed, the latter can be defined as follows: Energy is the ability to do work, this is some measure of the "resource" available in the mechanical system for its performance. In addition, energy is a measure of the transition from one type of motion to another.
In biomechanics, the following main types of energy are considered:
- * potential, depending on the relative position of the elements of the mechanical system of the human body;
- * kinetic forward movement;
- * kinetic rotary motion;
- * potential deformation of the elements of the system;
- * thermal;
- * metabolic processes.
The total energy of a biomechanical system is equal to the sum of all the listed types of energy.
By lifting the body, compressing the spring, it is possible to accumulate energy in the form of potential for its subsequent use. Potential energy is always associated with one or another force acting from one body to another. For example, the Earth acts by gravity on a falling object, a compressed spring - on a ball, a stretched bowstring - on an arrow.
Potential energy is the energy that a body possesses due to its position in relation to other bodies, or due to the mutual arrangement of parts of one body.
Therefore, the gravitational force and the elastic force are potential.
Gravitational potential energy: En = m * g * h
Potential energy of elastic bodies:
where k is the stiffness of the spring; x is its deformation.
From the above examples, it can be seen that energy can be stored in the form of potential energy (raise a body, compress a spring) for later use.
In biomechanics, two types of potential energy are considered and taken into account: due to the mutual arrangement of the links of the body to the surface of the Earth (gravitational potential energy); associated with the elastic deformation of the elements of the biomechanical system (bones, muscles, ligaments) or any external objects (sports equipment, inventory).
Kinetic energy is stored in the body during movement. A moving body does work at the expense of its loss. Since the links of the body and the human body perform translational and rotational movements, the total kinetic energy (Ek) will be equal to:
where m is the mass, V is the linear velocity, J is the moment of inertia of the system, u is the angular velocity.
Energy enters the biomechanical system due to the flow of metabolic metabolic processes in the muscles. The change in energy, as a result of which work is done, is not a highly efficient process in a biomechanical system, that is, not all energy goes into useful work. Part of the energy is lost irreversibly, turning into heat: only 25% is used to do work, the remaining 75% is converted and dissipated in the body.
For a biomechanical system, the law of conservation of energy of mechanical movement is applied in the form:
Epol \u003d Ek + Epot + U,
where Еpol is the total mechanical energy of the system; Ek - kinetic energy of the system; Epot - potential energy of the system; U is the internal energy of the system, representing mainly thermal energy.
The total energy of the mechanical movement of a biomechanical system is based on the following two sources of energy: metabolic reactions in the human body and mechanical energy external environment(deformable elements of sports equipment, inventory, supporting surfaces; opponents in contact interactions). This energy is transmitted through external forces.
A feature of energy production in a biomechanical system is that one part of the energy during movement is spent on performing the necessary motor action, the other goes to the irreversible dissipation of the stored energy, the third is stored and used during subsequent movement. When calculating the energy expended during movements and the mechanical work performed in this case, the human body is represented as a model of a multi-link biomechanical system similar to the anatomical structure. The movements of an individual link and the movement of the body as a whole are considered in the form of two simpler types of movement: translational and rotational.
The total mechanical energy of some i-th link (Epol) can be calculated as the sum of potential (Epot) and kinetic energy (Ek). In turn, Ek can be represented as the sum of the kinetic energy of the center of mass of the link (Ek.c.m.), in which the entire mass of the link is concentrated, and the kinetic energy of the rotation of the link relative to the center of mass (Ek. Vr.).
If the kinematics of the link movement is known, this general expression for the total energy of the link will have the form:
newton kinetic momentum
where mi is the mass of the i-th link; g - free fall acceleration; hi is the height of the center of mass above some zero level (for example, above the Earth's surface at a given location); - the speed of the translational movement of the center of mass; Ji is the moment of inertia of the i-th link relative to the instantaneous axis of rotation passing through the center of mass; u - instantaneous angular velocity of rotation relative to the instantaneous axis.
The work on changing the total mechanical energy of the link (Ai) during the operation from the moment t1 to the moment t2 is equal to the difference in the energy values at the final (Ep(t2)) and initial (Ep(t1)) moments of motion:
Naturally, in this case, the work is spent on changing the potential and kinetic energy of the link.
If the amount of work Аi > 0, that is, the energy has increased, then they say that positive work has been done on the link. If AI< 0, то есть энергия звена уменьшилась, - отрицательная работа.
The mode of work for changing the energy of a given link is called overcoming, if the muscles perform positive work on the link; inferior if the muscles do negative work on the link.
Positive work is done when the muscle contracts against an external load, goes to accelerate the links of the body, the body as a whole, sports equipment, etc. Negative work is done if the muscles resist stretching due to the action of external forces. This happens when lowering the load, going down the stairs, counteracting a force that exceeds the strength of the muscles (for example, in arm wrestling).
seen Interesting Facts the ratio of positive and negative muscle work: negative muscle work is more economical than positive; Preliminary performance of negative work increases the value and efficiency of the positive work that follows it.
The greater the speed of movement of the human body (during track and field athletics, skating, skiing, etc.), the greater part of the work is spent not on a useful result - moving the body in space, but on moving the links relative to the GMC. Therefore, in high-speed modes, the main work is spent on accelerating and decelerating the body links, since with an increase in speed, the acceleration of the movement of the body links sharply increases.
Energy is the most important concept in mechanics. What is energy. There are many definitions, and here is one of them.
What is energy?
Energy is the ability of a body to do work.
Consider a body that was moving under the influence of some forces and changed its speed from v 1 → to v 2 → . In this case, the forces acting on the body have done a certain amount of work A.
The work of all forces acting on the body is equal to the work of the resultant force.
F p → = F 1 → + F 2 →
A \u003d F 1 s cos α 1 + F 2 s cos α 2 \u003d F p cos α.
Let's establish a connection between the change in the speed of the body and the work done by the forces acting on the body. For simplicity, we will assume that a single force F → acts on the body, directed along a straight line. Under the action of this force, the body moves uniformly accelerated and in a straight line. In this case, the vectors F → , v → , a → , s → coincide in direction and can be considered as algebraic quantities.
The work of the force F → is equal to A = F s . The movement of the body is expressed by the formula s = v 2 2 - v 1 2 2 a. From here:
A = F s = F v 2 2 - v 1 2 2 a = m a v 2 2 - v 1 2 2 a
A = m v 2 2 - m v 1 2 2 = m v 2 2 2 - m v 1 2 2 .
As you can see, the work done by the force is proportional to the change in the square of the speed of the body.
Definition. Kinetic energy
The kinetic energy of a body is half the product of the body's mass times the square of its speed.
Kinetic energy is the energy of the motion of a body. At zero speed it is zero.
Kinetic energy theorem
Let us turn again to the considered example and formulate a theorem on the kinetic energy of a body.
Kinetic energy theorem
The work of the force applied to the body is equal to the change in the kinetic energy of the body. This statement is also true when the body moves under the action of a force changing in magnitude and direction.
A \u003d E K 2 - E K 1.
Thus, the kinetic energy of a body of mass m, moving at a speed v → , is equal to the work that the force must do to accelerate the body to this speed.
A = m v 2 2 = E K .
To stop the body, you need to do work
A = - m v 2 2 = - E K
Kinetic energy is the energy of motion. Along with kinetic energy, there is also potential energy, that is, the energy of the interaction of bodies, which depends on their position.
For example, a body is raised above the ground. The higher it is raised, the greater the potential energy will be. When a body falls down under the influence of gravity, this force does work. Moreover, the work of gravity is determined only by the vertical displacement of the body and does not depend on the trajectory.
Important!
In general, one can talk about potential energy only in the context of those forces whose work does not depend on the shape of the body's trajectory. Such forces are called conservative.
Examples of conservative forces: gravity, elastic force.
When a body moves vertically upwards, gravity does negative work.
Consider an example where the ball has moved from a point with height h 1 to a point with height h 2 .
In this case, the force of gravity has done work equal to
A \u003d - m g (h 2 - h 1) \u003d - (m g h 2 - m g h 1) .
This work is equal to the change in m g h taken with the opposite sign.
The value of E P \u003d m g h is the potential energy in the gravity field. At the zero level (on the ground) the potential energy of the body is zero.
Definition. Potential energy
Potential energy is part of the total mechanical energy of the system in the field of conservative forces. Potential energy depends on the position of the points that make up the system.
We can talk about potential energy in the gravity field, potential energy of a compressed spring, and so on.
The work of gravity is equal to the change in potential energy, taken with the opposite sign.
A \u003d - (E P 2 - E P 1) .
It is clear that the potential energy depends on the choice of the zero level (the origin of the OY axis). We emphasize that the physical meaning is change potential energy when moving bodies relative to each other. With any choice of the zero level, the change in potential energy will be the same.
When calculating the movement of bodies in the Earth's gravitational field, but at considerable distances from it, one must take into account the law of universal gravitation (the dependence of the force of gravity on the distance to the center of the Earth). We give a formula expressing the dependence of the potential energy of the body.
E P = - G m M r .
Here G is the gravitational constant, M is the mass of the Earth.
Potential energy of a spring
Let's imagine that in the first case we took a spring and lengthened it by x. In the second case, we first lengthened the spring by 2x and then shortened it by x. In both cases, the spring was stretched by x , but this was done in different ways.
In this case, the work of the elastic force with a change in the length of the spring by x in both cases was the same and equal to
A y p p \u003d - A \u003d - k x 2 2.
The value of E y p p \u003d k x 2 2 is called the potential energy of a compressed spring. It is equal to the work of the elastic force during the transition from a given state of the body to a state with zero deformation.
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All previously introduced values characterized only mechanical motion. However, there are many forms of motion of matter; there is a constant transition from one form of motion to another. It is necessary to introduce a physical quantity that characterizes the motion of matter in all forms of its existence, with the help of which it would be possible to quantitatively compare various forms of motion of matter.
Energy- a measure of the movement of matter in all its forms. The main property of all types of energy is interconvertibility. The amount of energy that a body possesses is determined by the maximum work that the body can do, having used up its energy completely. Energy is numerically equal to the maximum work that the body can do, and is measured in the same units as the work. During the transition of energy from one type to another, it is necessary to calculate the energy of the body or system before and after the transition and take their difference. This difference is called work: .
Thus, the physical quantity characterizing the ability of a body to perform work is called energy.
The mechanical energy of a body can be due either to the movement of the body at a certain speed, or to the presence of the body in a potential field of forces.
Kinetic energy.
The energy possessed by a body due to its motion is called kinetic. The work done on the body is equal to the increment of its kinetic energy. Let's find this work for the case when the resultant of all forces applied to the body is equal to .
The work done by the body due to kinetic energy is equal to the loss of this energy.
Potential energy.
If at each point in space other bodies act on the body with a force, the magnitude of which may be different at different points, the body is said to be in a field of forces or a force field.
If the lines of action of all these forces pass through one point - the force center of the field - and the magnitude of the force depends only on the distance to this center, then such forces are called central, and the field of such forces is called central (gravitational, electric field of a point charge).
The field of forces constant in time is called stationary.
A field in which the lines of action of forces are parallel straight lines located at the same distance from each other is homogeneous.
All forces in mechanics are divided into conservative and non-conservative (or dissipative).
Forces whose work does not depend on the shape of the trajectory, but is determined only by the initial and final positions of the body in space, are called conservative.
The work of conservative forces along a closed path is zero. All central forces are conservative. The forces of elastic deformation are also conservative forces. If only conservative forces act in the field, the field is called potential (gravitational field).
Forces whose work depends on the shape of the path are called non-conservative (friction forces).
Potential energy is called a part of the total mechanical energy of the system, which is determined only by the mutual arrangement of the bodies that make up the system, and the nature of the forces of interaction between them. Potential energy is the energy possessed by bodies or body parts due to their relative position.
The concept of potential energy is introduced as follows. If the body is in a potential field of forces (for example, in the gravitational field of the Earth), each point of the field can be associated with some function (called potential energy) so that the work A 12, performed over the body by the forces of the field when it moves from an arbitrary position 1 to another arbitrary position 2, was equal to the decrease of this function on the path 1®2:
where and are the values of the potential energy of the system in positions 1 and 2.
The written relation makes it possible to determine the potential energy value up to some unknown additive constant. However, this circumstance does not matter, because. all ratios include only the difference in potential energies corresponding to two positions of the body. In each specific problem, it is agreed to consider the potential energy of a certain position of the body equal to zero, and take the energy of other positions relative to the zero level. The specific form of the function depends on the nature of the force field and the choice of the zero level. Since the zero level is chosen arbitrarily, it can have negative values. For example, if we take as zero the potential energy of a body located on the surface of the Earth, then in the field of gravity forces near the earth's surface, the potential energy of a body of mass m, raised to a height h above the surface, is (Fig. 5).
where is the displacement of the body under the action of gravity;
The potential energy of the same body lying at the bottom of a well with depth H is equal to
In the considered example, it was about the potential energy of the Earth-body system.
Potential energy can be possessed not only by a system of interacting bodies, but by a single body. In this case, the potential energy depends on the relative position of the body parts.
Let us express the potential energy of an elastically deformed body.
The potential energy of elastic deformation, if we assume that the potential energy of an undeformed body is zero; k- coefficient of elasticity, x- deformation of the body.
In the general case, a body can simultaneously have both kinetic and potential energies. The sum of these energies is called full mechanical energy body: .
The total mechanical energy of a system is equal to the sum of its kinetic and potential energies. The total energy of the system is equal to the sum of all types of energy that the system possesses.
The law of conservation of energy is the result of a generalization of many experimental data. The idea of this law belongs to Lomonosov, who stated the law of conservation of matter and motion, and the quantitative formulation was given by the German physician Mayer and the naturalist Helmholtz.
Law of conservation of mechanical energy: in the field of only conservative forces, the total mechanical energy remains constant in an isolated system of bodies. The presence of dissipative forces (friction forces) leads to dissipation (scattering) of energy, i.e. converting it into other types of energy and violating the law of conservation of mechanical energy.
The law of conservation and transformation of total energy: the total energy of an isolated system is a constant value.
Energy never disappears and does not appear again, but only changes from one form to another in equivalent quantities. This is the physical essence of the law of conservation and transformation of energy: the indestructibility of matter and its motion.
