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

Zerowa zasada termodynamiki mówi, że jeśli dowolne dwa ciała są w równowadze termicznej z trzecim ciałem, są one również w równowadze termicznej ze sobą.
Aby zrozumieć to eksperymentalnie, rozważ trzy zlewki wypełnione wodą o trzech różnych temperaturach.
Po połączeniu zlewki A z B i zlewki B z C nastąpi wymiana ciepła.
Po pewnym czasie woda w zlewce A osiąga równowagę termiczną z wodą w zlewce B, a woda w zlewce B osiąga równowagę z wodą w zlewce C.
Podczas rejestrowania temperatury zlewek obserwuje się jednolitą temperaturę we wszystkich trzech zlewkach, co odpowiada zerowej zasadzie termodynamiki.
Najważniejszym zastosowaniem zerowej zasady termodynamiki są różne typy termometrów.
Kiedy termometr jest używany do pomiaru temperatury ciała, osiąga równowagę termiczną poprzez zmianę własnej temperatury.
Tak więc zmierzona temperatura ciała jest w rzeczywistości temperaturą termometru.

<ol>
	<li>Protokół OpenStax. (2019). Fizyka uniwersytecka Vol. 2. [Wersja internetowa]. Pobrane z <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>

zerowa zasada termodynamiki

Eksperymentalnie, jeśli obiekt A jest w równowadze z obiektem B, a obiekt B jest w równowadze z obiektem C, wówczas obiekt A jest w równowadze z obiektem C. To stwierdzenie o przechodniości nazywa się „zerową zasadą termodynamiki”. Na przykład blok zimnego metalu i blok gorącego metalu umieszcza się na metalowej płycie w temperaturze pokojowej. Ostatecznie zimny blok i płyta znajdą się w równowadze termicznej. Ponadto gorący blok i płyta będą w równowadze termicznej. Na podstawie prawa zerowego możemy stwierdzić, że zimny i gorący blok również znajdują się w równowadze termicznej.

Brytyjski fizyk Ralph Fowler zasugerował liczbę „zero” w latach trzydziestych XX wieku. W tamtym czasie nazwano i ponumerowano już pierwszą, drugą i trzecią zasadę termodynamiki. Rzadko kiedy podawano prawo zerowe, ale należało je omówić przed innymi, więc Fowler podał mniejszą liczbę.

Rozważmy teraz przypadek, w którym A jest termometrem. Prawo zera mówi nam, że jeśli A odczyta pewną temperaturę będąc w równowadze z B, a następnie zetknie się z C, to nie będzie wymieniać energii z C; dlatego odczyt temperatury pozostanie taki sam. Innymi słowy, jeśli dwa obiekty znajdują się w równowadze termicznej, mają tę samą temperaturę.

Zerowa zasada termodynamiki

Doświadczalnie, jeśli obiekt A jest w równowadze z obiektem B, a obiekt B jest w równowadze z obiektem C, to obiekt A jest w równowadze z obiektem C.

Education

JoVE Core

Physics

Fizyka

Unit 1

Jednostka 1

Temperature and Heat

Temperatura i ciepło

KEY TERMS AND CONCEPTS

Kluczowe terminy i pojęcia

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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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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