Chapter 11 — Thermodynamics

Thermodynamics is the branch of physics dealing with heat, temperature, and energy conversion. It studies laws governing thermal energy transformation between heat and work, exemplified by processes like friction producing heat or steam engines converting heat to work.

Thermodynamics studies laws governing thermal energy and inter-conversion of heat and other forms of energy. The chapter covers the Zeroth Law (temperature equality in thermal equilibrium), the First Law (conservation of energy through ∆Q = ∆U + ∆W), specific heat capacity, thermodynamic state variables, five key processes (isothermal, adiabatic, isochoric, isobaric, cyclic), the Second Law (limiting heat engine efficiency), and the Carnot engine achieving maximum theoretical efficiency η = 1 − T₂/T₁.

1. 01Zeroth Law: two systems in thermal equilibrium with a third system separately are in thermal equilibrium with each other; establishes temperature concept
2. 02Heat (energy transfer via temperature difference) and work (energy transfer via other means) are two distinct modes of changing system internal energy
3. 03First Law: ∆Q = ∆U + ∆W states that heat supplied equals internal energy change plus work done by system
4. 04Internal energy is a state variable depending only on system state (pressure, volume, temperature), independent of path taken
5. 05Second Law: no heat engine can achieve 100% efficiency; Carnot engine provides maximum theoretical efficiency of η = 1 − T₂/T₁ between hot (T₁) and cold (T₂) reservoirs
6. 06Adiabatic process: no heat exchange (Q = 0); isothermal process: constant temperature (T fixed); isochoric: constant volume (V fixed); isobaric: constant pressure (P fixed)