Thermal Equilibrium
Defining the state where there is no net flow of heat between two systems in thermal contact, implying they are at the same temperature.
What is Thermal Equilibrium?
A state reached by two or more systems in thermal contact, characterized by no net flow of heat energy between them, implying they are at the same temperature.
Key points
- Define thermal equilibrium.
- State and explain the Zeroth Law of Thermodynamics.
- Understand the significance of the Zeroth Law for temperature measurement.
- Differentiate between thermal contact and thermal equilibrium.
Common exam trap
Confusing thermal equilibrium with thermal contact.
Definitions
- Term
Thermal Equilibrium
- Meaning
A state reached by two or more systems in thermal contact, characterized by no net flow of heat energy between them, implying they are at the same temperature.
- Term
Zeroth Law of Thermodynamics
- Meaning
If two systems are separately in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
- Term
Temperature
- Meaning
A physical quantity that expresses hotness or coldness and is a measure of the average kinetic energy of the particles in a system; systems in thermal equilibrium have the same temperature.
Learning objectives
Define thermal equilibrium.
State and explain the Zeroth Law of Thermodynamics.
Understand the significance of the Zeroth Law for temperature measurement.
Differentiate between thermal contact and thermal equilibrium.
Prerequisites
Understanding of heat and temperature.
Concept of thermal contact.
Basic understanding of energy transfer.
Common mistakes
Confusing thermal equilibrium with thermal contact.
Assuming heat transfer stops completely in thermal contact, rather than net transfer becoming zero.
Overlooking the role of the 'third system' in the Zeroth Law.
Confusing the Zeroth Law with the First or Second Laws of Thermodynamics.
Keywords
Thermal Equilibrium
Zeroth Law of Thermodynamics
Temperature
Heat Transfer
Thermal Contact
Thermometry
Practice preview
Which of the following statements about thermal equilibrium is INCORRECT?…
medium
When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This statement is known as:…
easy
Two objects A and B are in thermal equilibrium. Object C is in thermal equilibrium with object A. What is the relationship between objects B and C?…
easy