Uploaded August 2025 | Updated September 2026, 2 weeks ago
Laws of Thermodynamics
Dr. DeBacco
Zeroth Law
The 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 establishes the concept of temperature, allowing it to be measured and compared across systems.
Essentially, it ensures that temperature is a consistent, transitive property.
First Law (Law of Energy Conservation)
First Law (Law of Energy Conservation): Energy cannot be created or destroyed, only transferred or converted from one form to another.
The change in internal energy of a system (ΔU) equals the heat added (Q) minus the work done by the system (W):
ΔU = Q−W
Second Law (Law of Entropy)
Second Law (Law of Entropy): In an isolated system, entropy (disorder) tends to increase over time.
Energy transformations are not 100% efficient, and some energy is always lost as unusable heat.
This implies that natural processes are irreversible and favor increasing disorder unless external work is done.
Third Law
Third Law: As the temperature of a system approaches absolute zero (0 Kelvin), the entropy of a perfect crystal approaches zero.
This means that at absolute zero, a perfectly ordered system has no randomness, providing a reference point for measuring entropy.
Link to Lecture Slides: drive.google.com/file/d/1n8TDsVfqGoI-L2kPbE2L5hKI47de2i8t/view?usp=drive_link
*Due to the description character limit the full work cited for "Laws of Thermodynamics" can be viewed at... docs.google.com/document/d/1V_2n330mHYJz5gqnmOxE1LH22Wi1CKaz/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
Laws of Thermodynamics
Dr. DeBacco
Zeroth Law
The 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 establishes the concept of temperature, allowing it to be measured and compared across systems.
Essentially, it ensures that temperature is a consistent, transitive property.
First Law (Law of Energy Conservation)
First Law (Law of Energy Conservation): Energy cannot be created or destroyed, only transferred or converted from one form to another.
The change in internal energy of a system (ΔU) equals the heat added (Q) minus the work done by the system (W):
ΔU = Q−W
Second Law (Law of Entropy)
Second Law (Law of Entropy): In an isolated system, entropy (disorder) tends to increase over time.
Energy transformations are not 100% efficient, and some energy is always lost as unusable heat.
This implies that natural processes are irreversible and favor increasing disorder unless external work is done.
Third Law
Third Law: As the temperature of a system approaches absolute zero (0 Kelvin), the entropy of a perfect crystal approaches zero.
This means that at absolute zero, a perfectly ordered system has no randomness, providing a reference point for measuring entropy.
Link to Lecture Slides: drive.google.com/file/d/1n8TDsVfqGoI-L2kPbE2L5hKI47de2i8t/view?usp=drive_link
*Due to the description character limit the full work cited for "Laws of Thermodynamics" can be viewed at... docs.google.com/document/d/1V_2n330mHYJz5gqnmOxE1LH22Wi1CKaz/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
