Download "Первый закон термодинамики | Физика 10 класс #41 | Инфоурок"

Please wait. We're preparing links for easy ad-free video watching and downloading.

Previous video: Работа и мощность электрического тока. Работа тока | Физика 8 класс #19 | Инфоурок Next video: Электрические цепи. Последовательное и параллельное соединение | Физика 10 класс #54 | Инфоурок

Электрические цепи. Последовательное и параллельное соединение | Физика 10 класс #54 | Инфоурок

Электрические цепи. Последовательное и параллельное соединение | Физика 10 класс #54 | Инфоурок

Channel: ИНФОУРОК

Работа и мощность электрического тока. Работа тока | Физика 8 класс #19 | Инфоурок

Работа и мощность электрического тока. Работа тока | Физика 8 класс #19 | Инфоурок

Channel: ИНФОУРОК

инфоурок

школа

видеоуроки

10 класс

физика

00:00:00

[music] the

00:00:11

first law of thermodynamics application of the

00:00:14

first law of thermodynamics to various

00:00:17

processes

00:00:22

the first law of thermodynamics is the law of

00:00:24

conservation of energy

00:00:26

extended to thermal phenomena, it

00:00:29

establishes the reasons on which the

00:00:32

change in the internal energy of a

00:00:34

macroscopic body depends,

00:00:38

if a friction force acts in a closed system,

00:00:41

then the mechanical energy of the system will

00:00:44

decrease, for example the

00:00:47

mechanical energy of a car

00:00:50

moving on a horizontal road with the

00:00:52

engine turned off decreases, as

00:00:54

evidenced by a

00:00:55

decrease in its speed, while

00:00:58

heating of the rubbing surfaces is observed,

00:01:01

that is, an increase in internal energy in

00:01:05

this example, the mechanical energy of

00:01:07

the system is not conserved; part of it is

00:01:10

converted into internal energy

00:01:14

based on similar observations and a

00:01:16

generalization of experimental facts

00:01:19

the law of conservation of energy was formulated;

00:01:21

energy in nature does not arise from nothing

00:01:24

and does not disappear; the amount of energy

00:01:28

invariably it only passes from one

00:01:31

form to another; the

00:01:33

law of conservation of energy is a

00:01:36

fundamental law of nature; it is

00:01:39

always and everywhere true in relation

00:01:41

to any natural phenomenon; there is not a

00:01:44

single case known when this the great

00:01:47

law was not observed

00:01:51

when considering bodies in thermodynamics, we

00:01:53

believe that their mechanical energy is

00:01:55

constant

00:01:57

and only the internal energy of

00:01:59

each body changes.

00:02:02

Until now, we have considered cases in

00:02:04

which the internal energy of the system

00:02:07

changed either due to heat transfer

00:02:10

or when doing work in real

00:02:13

life, the internal energy of the system can

00:02:16

change simultaneously, both due to the

00:02:18

work being done and due to heat exchange

00:02:21

with surrounding bodies, the

00:02:24

first law of thermodynamics is formulated

00:02:27

precisely for such general cases, the change in the

00:02:31

internal energy of a system during

00:02:34

its transition from one state to another is

00:02:36

equal to the sum of the work of external forces on

00:02:39

the system and the amount of heat transferred to my

00:02:44

first law of thermodynamics can be

00:02:46

write differently, instead of the work of external forces

00:02:50

on the system, consider the work of the

00:02:53

system on external forces, taking into account that the work of

00:02:56

external forces on the system is equal to the work of the

00:02:59

system with the opposite sign, we obtain

00:03:02

the amount of heat transferred to the system

00:03:05

goes to the system to perform work

00:03:07

against external forces and to increase its

00:03:11

internal energy

00:03:15

if the system is isolated then the

00:03:17

external bodies do not interact with the

00:03:20

system, which means the work of external forces

00:03:23

is zero and the system does not exchange

00:03:26

heat with the surrounding bodies;

00:03:29

in this case, according to the first law of

00:03:32

thermodynamics,

00:03:33

changes in the internal energy of the system

00:03:35

are equal to 0;

00:03:36

therefore, the internal energy of an isolated

00:03:40

system remains unchanged;

00:03:45

while scientists have attempted to

00:03:47

create a perpetual motion machine, then There is

00:03:49

such a device that would perform

00:03:52

mechanical work only due to

00:03:54

internal energy without receiving energy

00:03:58

from the outside, it is difficult to name the first author of

00:04:00

such a plan. The

00:04:02

earliest description of a perpetual motion machine

00:04:06

was found in the Indian poet, mathematician and

00:04:09

astronomer

00:04:10

Acharya Bhaskara, who lived in the 12th century in

00:04:14

a poem

00:04:15

dating back to approximately 1150. The

00:04:20

law of thermodynamics follows

00:04:23

that the creation of a perpetual motion machine is

00:04:25

impossible if no energy is supplied to the system,

00:04:29

then work on external bodies can

00:04:32

only be done by reducing the

00:04:35

internal energy

00:04:37

after the internal energy of

00:04:39

the system is equal to zero, the engine

00:04:42

stops working, the

00:04:46

internal

00:04:48

systems of bodies change when

00:04:50

work is done against external forces and

00:04:53

when transferring heat to

00:04:54

other things in each state, the system

00:04:57

has a certain amount of

00:04:59

internal energy, work and the amount of

00:05:03

heat is

00:05:04

not contained in the body but characterizes the

00:05:06

process of changing its internal energy. The

00:05:12

first law of thermodynamics

00:05:13

allows us to draw important conclusions

00:05:15

about the nature of the ongoing processes.

00:05:19

Let us consider this law in application to

00:05:21

various processes in which one of the

00:05:23

physical quantities remains unchanged

00:05:29

under and take the case when the system

00:05:31

is an ideal gas

00:05:34

and in the sugar process the volume of the gas does not

00:05:37

change and therefore the work of the gas is

00:05:39

zero, the

00:05:41

change in the internal energy of the gas

00:05:44

according to the first law of thermodynamics

00:05:46

is equal to the amount of heat transferred to it

00:05:50

if the system is transferred a certain

00:05:53

amount of heat,

00:05:54

then its internal energy increases

00:05:56

and the gas heats up,

00:06:00

if the system gives off heat, then the gas

00:06:03

cools and its internal energy

00:06:06

decreases

00:06:10

during an isothermal process. the

00:06:28

work of a gas against

00:06:31

external forces, if the gas receives heat, then

00:06:34

it does positive work and at the same time

00:06:37

expands,

00:06:39

if, on the contrary, the gas gives off heat to

00:06:41

surrounding bodies, then it does

00:06:44

negative work and at the same time

00:06:46

is compressed, and the work of external forces on the gas

00:06:50

is positive

00:06:52

on the bar process according to the first

00:06:54

law of thermodynamics

00:06:56

transferred to the gas the amount of heat

00:06:59

goes to change its internal energy

00:07:02

and to perform work at a constant

00:07:05

pressure; the amount of heat transferred to

00:07:08

the system

00:07:09

is equal to the sum of the change in internal energy

00:07:12

and the product of gas pressure and the

00:07:15

change in volume; a

00:07:19

process occurring in a heat-

00:07:21

isolated system that does not

00:07:23

receive or give off heat to surrounding

00:07:26

bodies; such a process is called

00:07:29

adiabatic in an adiabatic process, according to the

00:07:32

first law of thermodynamics, a change in

00:07:35

internal energy occurs only

00:07:38

due to work done

00:07:41

if external bodies perform

00:07:44

positive work on a gas, for example, when a gas is compressed,

00:07:47

its internal energy increases

00:07:50

accordingly, the temperature of the gas

00:07:52

increases and vice versa, if the gas itself

00:07:56

does positive work on

00:07:58

external bodies, then its internal

00:08:01

energy is reduced and the gas is cooled

00:08:07

heating the air during rapid compression

00:08:09

used in diesel engines they

00:08:12

have the following operating principle:

00:08:15

atmospheric air is sucked into the cylinder

00:08:17

which is compressed at high speed

00:08:20

during compression the temperature of the air in the

00:08:23

cylinder increases greatly at the end of the compression stroke

00:08:29

liquid fuel is injected into the cylinder through a special nozzle at

00:08:32

this moment the air temperature is so

00:08:35

high that the fuel flares up

00:08:37

diesel engines have a higher

00:08:39

efficiency than

00:08:42

conventional ones but are more massive and difficult to

00:08:45

manufacture and operate

00:08:49

using the first law of thermodynamics

00:08:51

we can explain the formation of clouds in the

00:08:54

earth's atmosphere;

00:08:56

air heated near the surface of the earth

00:08:58

rises up in the upper layers

00:09:01

atmosphere pressure is significantly lower than

00:09:03

in the lower ones, therefore the rising air

00:09:06

expands; this expansion occurs under

00:09:09

conditions close to adiabatic and

00:09:12

is therefore accompanied by strong cooling

00:09:16

as a result, water vapor condenses

00:09:17

and forms clouds.

00:09:23

Consider a heat up

00:09:25

system consisting of several bodies

00:09:27

having initially

00:09:29

different temperatures, for example,

00:09:32

heat exchange between hot water in glass

00:09:34

and lowered into water with a cold spoon,

00:09:37

we will assume that the system is sufficiently

00:09:40

isolated from the surrounding bodies and its

00:09:43

internal energy does not change; no

00:09:46

work is done inside this system

00:09:50

after the onset of thermal equilibrium,

00:09:52

according to the first law of thermodynamics, the

00:09:55

increase in internal energy of the spoon in the

00:09:58

glass will be equal to the amount of heat

00:10:01

given by the water

00:10:03

then the sum of the change in internal energy of the

00:10:05

spoon and water is equal to 0

00:10:09

and the sum of the amount of heat received by both

00:10:11

spoon and the amount of heat received by

00:10:14

water is equal to 0.

00:10:29

heat

00:10:32

received and given off by the bodies of an

00:10:34

isolated system is equal to 0, we

00:10:37

have obtained the heat balance equation, the

00:10:44

internal energy of an ideal gas does not

00:10:47

change only during an isothermal

00:10:49

process, in sugar

00:10:51

it changes due to heat exchange, and during an

00:10:54

isobaric process, the internal energy of a

00:10:57

gas

00:10:58

changes both due to heat transfer

00:11:01

and due to the work done

00:11:03

in in a thermally insulated system, an

00:11:06

adiabatic process occurs; the change in the energy of the

00:11:09

system in this process is equal to the work of

00:11:12

external forces

Description:

Видеоуроки являются идеальными помощниками при изучении новых тем, закреплении материала, для обычных и факультативных занятий, для групповой и индивидуальной работы. Они содержат оптимальное количество графической и анимационной информации для сосредоточения внимания и удержания интереса ребят без отвлечения от сути занятия. Каждый видеоурок озвучен профессиональным мужским голосом, четким и приятным для восприятия. Ученики ценят оригинальность подачи материала, родители радуются повышению отметок детей, а учителя в восторге от эффекта и экономии времени и денег при подготовке к урокам. ____________________________________ ★Инфоурок★ Крупнейший в России образовательный онлайн-проект МЫ ПРЕДЛАГАЕМ: ✓ Курсы дополнительного образования детей и взрослых: https://infourok.ru/ ✓ Тесты для учителей и воспитателей: https://infourok.ru/tests ✓ Самые массовые международные дистанционные олимпиады: https://infourok.ru/konkurs ✓ Видеоуроки по 14 предметам: https://school.infourok.ru/videouroki?authChecked=true ✓ Каталог репетиторов: https://school.infourok.ru/?authChecked=true ✓ Библиотека методических материалов для учителей: https://infourok.ru/biblioteka Адрес редакции и издательства: 214011, РФ, г. Смоленск, ул. Верхне-Сенная, 4. [email protected] © 2012–2017 Издатель: Проект «Инфоурок»

Preparing download options

Popular

HD video

Only sound

All

* — If the video is playing in a new tab, go to it, then right-click on the video and select "Save video as..."

** — Link intended for online playback in specialized players

Questions about downloading video

How can I download "Первый закон термодинамики | Физика 10 класс #41 | Инфоурок" video?

http://unidownloader.com/ website is the best way to download a video or a separate audio track if you want to do without installing programs and extensions.
The UDL Helper extension is a convenient button that is seamlessly integrated into YouTube, Instagram and OK.ru sites for fast content download.
UDL Client program (for Windows) is the most powerful solution that supports more than 900 websites, social networks and video hosting sites, as well as any video quality that is available in the source.
UDL Lite is a really convenient way to access a website from your mobile device. With its help, you can easily download videos directly to your smartphone.

Which format of "Первый закон термодинамики | Физика 10 класс #41 | Инфоурок" video should I choose?

The best quality formats are FullHD (1080p), 2K (1440p), 4K (2160p) and 8K (4320p). The higher the resolution of your screen, the higher the video quality should be. However, there are other factors to consider: download speed, amount of free space, and device performance during playback.

Why does my computer freeze when loading a "Первый закон термодинамики | Физика 10 класс #41 | Инфоурок" video?

The browser/computer should not freeze completely! If this happens, please report it with a link to the video. Sometimes videos cannot be downloaded directly in a suitable format, so we have added the ability to convert the file to the desired format. In some cases, this process may actively use computer resources.

How can I download "Первый закон термодинамики | Физика 10 класс #41 | Инфоурок" video to my phone?

You can download a video to your smartphone using the website or the PWA application UDL Lite. It is also possible to send a download link via QR code using the UDL Helper extension.

How can I download an audio track (music) to MP3 "Первый закон термодинамики | Физика 10 класс #41 | Инфоурок"?

The most convenient way is to use the UDL Client program, which supports converting video to MP3 format. In some cases, MP3 can also be downloaded through the UDL Helper extension.

How can I save a frame from a video "Первый закон термодинамики | Физика 10 класс #41 | Инфоурок"?

This feature is available in the UDL Helper extension. Make sure that "Show the video snapshot button" is checked in the settings. A camera icon should appear in the lower right corner of the player to the left of the "Settings" icon. When you click on it, the current frame from the video will be saved to your computer in JPEG format.

What's the price of all this stuff?

It costs nothing. Our services are absolutely free for all users. There are no PRO subscriptions, no restrictions on the number or maximum length of downloaded videos.