Thermodynamics (Study Notes)
Overview
Thermodynamics is the study of the relationships between heat, work, and energy. It explains how thermal
energy is converted to and from other forms of energy and how it affects matter.
Zeroth Law of Thermodynamics
If two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with
each other. This law allows the definition of temperature.
First Law of Thermodynamics
This law is a statement of the conservation of energy: Energy cannot be created or destroyed, only
transformed.
Formula: U = Q - W
Where:
U = change in internal energy
Q = heat added to the system
W = work done by the system
Second Law of Thermodynamics
The Second Law introduces the concept of entropy and dictates the direction of heat transfer. It states that
the total entropy of an isolated system can never decrease over time, meaning natural processes are
irreversible.
Third Law of Thermodynamics
As the temperature of a system approaches absolute zero, the entropy of the system approaches a minimum
value. It is impossible to reach absolute zero in a finite number of steps.
Thermodynamic Processes
- Isothermal Process: Constant temperature (T = 0)
Overview
Thermodynamics is the study of the relationships between heat, work, and energy. It explains how thermal
energy is converted to and from other forms of energy and how it affects matter.
Zeroth Law of Thermodynamics
If two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with
each other. This law allows the definition of temperature.
First Law of Thermodynamics
This law is a statement of the conservation of energy: Energy cannot be created or destroyed, only
transformed.
Formula: U = Q - W
Where:
U = change in internal energy
Q = heat added to the system
W = work done by the system
Second Law of Thermodynamics
The Second Law introduces the concept of entropy and dictates the direction of heat transfer. It states that
the total entropy of an isolated system can never decrease over time, meaning natural processes are
irreversible.
Third Law of Thermodynamics
As the temperature of a system approaches absolute zero, the entropy of the system approaches a minimum
value. It is impossible to reach absolute zero in a finite number of steps.
Thermodynamic Processes
- Isothermal Process: Constant temperature (T = 0)
