Key Equations - Physics

Key Equations

12.2 First law of Thermodynamics: Thermal Energy and Work

ideal gas law	$P V = N k T$
first law of thermodynamics	$Δ U = Q - W$
pressure	$P = \frac{F}{A}$
pressure–volume work	$W = P Δ V$

12.3 Second Law of Thermodynamics: Entropy

change in entropy

Δ S = \frac{Q}{T}

12.4 Applications of Thermodynamics: Heat Engines, Heat Pumps, and Refrigerators

thermal efficiency of a heat engine	$E f f = \frac{W}{Q_{h}}$
work output for a cyclical process	$W = Q_{h} - Q_{c}$