Thermodynamics
Heat & Temperature, First Law, Second Law, Kinetic Theory, Entropy
Heat & Temperature
8 formulas
Heat required to change temperature of a substance.
Heat required for phase change at constant temperature.
Change in length due to temperature change.
Change in volume due to temperature change.
Rate of heat flow through a material.
Power radiated by a body due to its temperature. The emissivity ε covers real (gray) surfaces; setting ε = 1 gives the ideal blackbody form P = σAT⁴. This is the comprehensive, general form of the law.
Thermal analog of electrical resistance. ΔT = P × R_th.
Rate of cooling proportional to temperature difference. Solution: T(t) = T_env + (T₀ - T_env)e^(-ht).
First Law
8 formulas
Energy conservation: ΔU = Q - W (physics convention).
Work done by expanding gas (area under P-V curve).
Work for isothermal (constant T) expansion of ideal gas.
Internal energy depends only on temperature for ideal gas.
Relationship for adiabatic (no heat transfer) process. Also: T₁V₁^(γ-1) = T₂V₂^(γ-1).
Mayer relation: C_p is always greater than C_v by R for ideal gases.
Work done during adiabatic expansion or compression.
Heat content at constant pressure. ΔH = Q_p for constant pressure processes.
Second Law
6 formulas
Entropy change for reversible isothermal process.
Maximum efficiency of heat engine between two temperatures.
Efficiency of any heat engine.
Performance metric for refrigerators.
Performance metric for heat pumps. COP_HP = COP_R + 1.
Entropy change is at least Q/T. Equality holds for reversible processes.
Kinetic Theory
8 formulas
Equation of state for ideal gas.
Ideal gas law in terms of molecules.
Average translational KE of gas molecule.
RMS speed of gas molecules.
Average distance a molecule travels between collisions.
Pressure from molecular collisions. Connects microscopic motion to macroscopic pressure.
Speed at which Maxwell-Boltzmann distribution peaks.
Average speed of gas molecules from Maxwell-Boltzmann distribution.
Entropy
4 formulas
Entropy change for ideal gas between two states.
Statistical definition of entropy.
Maximum non-expansion work at constant T and P. ΔG < 0 for spontaneous processes.
Maximum work extractable at constant T and V. Also denoted A.
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