Thermodynamics

First Law of Thermodynamics: Internal energy change in a closed system is $\Delta U = Q - W$, where $Q$ is heat added and $W = \int P\,dV$ is work done by the system.

Calorimetry & State Changes: Sensible heat is $Q = mc\Delta T$; latent phase change heat is $Q = mL$.

Carnot Cycle & Efficiency: The maximum theoretical thermal efficiency of a heat engine operating between hot reservoir $T_H$ and cold reservoir $T_C$ is $\eta_{\text{Carnot}} = 1 - \frac{T_C}{T_H}$.

Entropy ($S$): Second Law requires $dS \ge \frac{dQ}{T}$, with total isolated universe entropy $\Delta S_{\text{univ}} \ge 0$.

Operating Instructions: Use the sidebar tab switcher to simulate the First Law, Zeroth Law thermal equilibrium, Heat Engine PV diagrams, Carnot efficiency, and Entropy.