Bodies in thermal equilibrium with a third are in equilibrium with each other.
If A and B are each in thermal equilibrium with C, they are in equilibrium with each other. This allows temperature measurement with thermometers. Heat flows only when there is a temperature difference.
A mercury thermometer reaches equilibrium with a cup of water before reading.
The zeroth law is what makes thermometers meaningful, since it allows temperature to be defined and measured consistently.
Bodies in thermal equilibrium with a third are in equilibrium with each other.
The zeroth law is what makes thermometers meaningful, since it allows temperature to be defined and measured consistently.
It lets you say two bodies have the same temperature if each is in equilibrium with a third, which is how a thermometer is used.
No. It is a statement about equilibrium, and a thermometer is simply a practical way to observe it.
Typical applications include calibrating a thermocouple against a reference bath, using a mercury or digital thermometer to compare two bodies and checking that two systems are in thermal equilibrium before a heat test.
Study "Properties and state" first (topic 3 of 105 in Thermodynamics & Fluids). It covers the groundwork this topic builds on.
Defines temperature. Thermometer principle. Basis for the temperature scale.
A mercury thermometer reaches equilibrium with a cup of water before reading.
The next topic is "Temperature scales", which builds directly on this one.
It is classed as Beginner in Thermodynamics & Fluids (topic 4 of 105). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
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