Physics Formulae/Thermodynamics Formulae
Lead Article: Tables of Physics Formulae
This article is a summary of the laws, principles, defining quantities, and useful formulae in the analysis of Thermodynamics.
Thermodynamics Laws
editZeroth Law of Thermodynamics |
(systems in thermal equilibrium) |
First Law of Thermodynamics | △Q = △U +△W
Heat energy transferred to system , from system Work done transferred to system by system |
Second Law of Thermodynamics | |
Third Law of Thermodynamics |
Thermodynamic Quantities
editQuantity (Common Name/s) | (Common Symbol/s) | Defining Equation | SI Units | Dimension |
---|---|---|---|---|
Number of Molecules | dimensionless | dimensionless | ||
Temperature | K | [Θ] | ||
Heat Energy | J | [M][L]2[T]-2 | ||
Latent Heat | J | [M][L]2[T]-2 | ||
Entropy | J K-1 | [M][L]2[T]-2 [Θ]-1 | ||
Heat Capacity (isobaric) | J K -1 | [M][L]2[T]-2 [Θ]-1 | ||
Specific Heat Capacity (isobaric) | J kg-1 K-1 | [L]2[T]-2 [Θ]-1 | ||
Molar Specific Heat
Capacity (isobaric) |
J K -1 mol-1 | [M][L]2[T]-2 [Θ]-1 [N]-1 | ||
Heat Capacity (isochoric) | J K -1 | [M][L]2[T]-2 [Θ]-1 | ||
Specific Heat Capacity (isochoric) | J kg-1 K-1 | [L]2[T]-2 [Θ]-1 | ||
Molar Specific Heat
Capacity (isochoric) |
J K -1 mol-1 | [M][L]2[T]-2 [Θ]-1 [N]-1 | ||
Internal Energy
Sum of all total energies which constitute the system |
J | [M][L]2[T]-2 | ||
Enthalpy | J | [M][L]2[T]-2 | ||
Gibbs Free Energy | J | [M][L]2[T]-2 | ||
Helmholtz Free Energy | J | [M][L]2[T]-2 | ||
Specific Latent Heat | J kg-1 | [L]2[T]-2 | ||
Ratio of Isobaric to
Isochoric Heat Capacity, Adiabatic Index |
dimensionless | dimensionless | ||
Linear Coefficient of Thermal Expansion | K-1 | [Θ]-1 | ||
Volume Coefficient of Thermal Expansion | K-1 | [Θ]-1 | ||
Temperature Gradient | No standard symbol | K m-1 | [Θ][L]-1 | |
Thermal Conduction Rate/
Thermal Current |
W = J s-1 | [M] [L]2 [T]-2 | ||
Thermal Intensity | W m-2 | [M] [L]-1 [T]-2 | ||
Thermal Conductivity | W m-1 K-1 | [M] [L] [T]-2 [Θ]-1 | ||
Thermal Resistance | m2 K W-1 | [L] [T]2 [Θ]1 [M]-1 | ||
Emmisivity Coefficient | Can only be found from experiment
for perfect reflector for perfect absorber (true black body) |
dimensionless | dimensionless |
Kinetic Theory
editIdeal Gas Law |
|
Translational Energy | |
Internal Energy |
Thermal Transitions
editAdiabatic |
|
Work by an Expanding Gas | Process
|
Isobaric Transition | |
Cyclic Process | |
Work, Isochoric | |
work, Isobaric | |
Work, Isothermal | |
Adiabatic Expansion |
|
Free Expansion |
Statistical Physics
editBelow are useful results from the Maxell-Boltzmann distribution for an ideal gas, and the implications of the Entropy quantity.
Degrees of Freedom | |
Maxwell-Boltzmann Distribution,
Mean Speed |
|
Maxwell-Boltzmann Distribution
Mode-Speed |
|
Root Mean Square Speed | |
Mean Free Path | ? |
Maxwell–Boltzmann Distribution | |
Multiplicity of Configurations | |
Microstate in one half of the box | |
Boltzmann's Entropy Equation | |
Irreversibility | |
Entropy | |
Entropy Change |
|
Entropic Force |
Thermal Transfer
editStefan-Boltzmann Law | |
Net Intensity Emmision/Absorbtion | |
Internal Energy of a Substance | |
Work done by an Expanding Ideal Gas | |
Meyer's Equation |
Thermal Efficiencies
editEngine Efficiency | |
Carnot Engine Efficiency | |
Refrigeration Performance | |
Carnot Refrigeration Performance |