Name: thermal equilibrium and the zeroth law
Uploaded: 2025-05-22T09:05:48.000Z
Duration: 1 min 14 s
Channel: JoVE

K12 Standards

Louisiana Student Standards for Science

High School

Chemistry

Energy

HS-PS3-4

Zeroth Law of Thermodynamics

Нулевой закон термодинамики гласит, что если любые два тела находятся в тепловом равновесии с третьим телом, то они также находятся в тепловом равновесии друг с другом.
Чтобы понять это экспериментально, рассмотрим три стакана, наполненные водой с тремя разными температурами.
После соединения стакана А с В и стакана Б с С произойдет теплопередача.
Через некоторое время вода в стакане А приходит в тепловое равновесие с водой в стакане В, а вода в стакане В приходит в равновесие с водой в стакане С.
При регистрации температуры мензурок во всех трех стаканах наблюдается равномерная температура, что соответствует нулевому закону термодинамики.
Наиболее значимым применением нулевого закона термодинамики являются различные типы термометров.
Когда термометр используется для измерения температуры тела, он достигает теплового равновесия за счет изменения собственной температуры.
Таким образом, измеренная температура тела фактически является температурой термометра.

<ol>
	<li>OpenStax. (2019). Университетская физика Том 2. [Веб-версия]. Получено из <a href="https://openstax.org/books/university-physics-volume-2/pages/1-1-temperature-and-thermal-equilibrium">https://openstax.org/books/university-physics-volume-2/pages/1-1-temperature-and-thermal-equilibrium</a></li>
</ol>

Нулевой закон термодинамики

Экспериментально, если объект A находится в равновесии с объектом B, а объект B находится в равновесии с объектом C, то объект A находится в равновесии с объектом C. Это утверждение о транзитивности называется "нулевым законом термодинамики". Например, холодный металлический блок и горячий металлический блок размещаются на металлической пластине при комнатной температуре. В конечном итоге, холодный блок и пластина находятся в тепловом равновесии. Кроме того, горячий блок и пластина находятся в тепловом равновесии. Из нулевого закона можно заключить, что холодный блок и горячий блок также находятся в тепловом равновесии.

Британский физик Ральф Фаулер предложил номер "нулевой" в 1930-х годах. К тому времени первые, вторые и третьи законы термодинамики уже были названы и пронумерованы. Нулевой закон редко упоминался, но перед обсуждением других законов его необходимо было упомянуть, поэтому Фаулер дал ему более маленький номер.

Теперь рассмотрим случай, когда A - это термометр. Нулевой закон говорит нам, что если A показывает определенную температуру, находясь в равновесии с B, и затем оно будет помещено в контакт с C, оно не будет обмениваться энергией с C; следовательно, его показания температуры останутся неизменными. Другими словами, если два объекта находятся в тепловом равновесии, они имеют одинаковую температуру.

Экспериментально, если объект А находится в равновесии с объектом В, а объект В находится в равновесии с объектом С, то объект А находится в равновесии с объектом С.

Education

JoVE Core

Physics

Физика

Unit 1

Раздел 1

Temperature and Heat

Температура и тепло

KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

thermal equilibrium and the zeroth law

The zeroth law of thermodynamics explains thermal equilibrium between objects. If object A is in equilibrium with object B, and object B is in equilibrium with object C, then object A is also in equilibrium with object C. This transitive relationship is the key idea behind the law.

A simple example uses metal blocks and a metal plate at room temperature. A cold metal block and a hot metal block are both placed on the plate. Over time, the cold block and the plate reach thermal equilibrium, and the hot block and the plate do too. By the zeroth law, the cold block and the hot block are then also in thermal equilibrium.

The law also helps explain how thermometers work. If a thermometer is in equilibrium with one object and then placed in contact with another object, it will not exchange energy with that object if their temperatures match. Its reading stays the same. In other words, two objects in thermal equilibrium have the same temperature.

The name zeroth law was suggested by British physicist Ralph Fowler in the 1930s. By then, the first, second, and third laws of thermodynamics had already been named. The zeroth law was less often stated, but it had to be discussed before the others, so Fowler gave it the smaller number.

Thermal Equilibrium and the Zeroth Law

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zeroth law of thermodynamics

The zeroth law of thermodynamics explains thermal equilibrium between objects. If object A is in equilibrium with object B, and object B is in equilibrium with object C, then object A is also in equilibrium with object C. This transitive relationship is the key idea behind the law. A simple example uses metal blocks and a metal plate at room temperature. A cold metal block and a hot metal block are both placed on the plate. Over time, the cold block and the plate reach thermal equilibrium, and...

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key terms and concepts

Learn how the zeroth law of thermodynamics shows that objects in thermal equilibrium have the same temperature and why this matters for thermometers.

Thermal Equilibrium and the Zeroth Law | JoVE K12

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HS-PS3-6

Thermal Equilibrium and the Zeroth Law

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