Chapter study guide

Thermodynamics is the study of heat, work, and how both transform to and from other forms of energy, particularly mechanical energy. At the core of this subject lie the laws of thermodynamics, which define how temperature, energy, and entropy work on the macroscopic level. The four laws—numbered zero through three!—define thermodynamic equilibrium, state energy conservation, describe how heat flows from hot to cold objects, and describe reversible and irreversible processes, respectively. In this chapter, you will learn the basic principles of the laws of thermodynamics and apply them to understand how steam engines in old locomotives, gasoline engines in cars, and refrigerators work.

By the end of this chapter you should be able to
state the laws of thermodynamics and provide examples of each;
define entropy and provide examples of reversible and irreversible systems;
explain the concept of absolute zero and its relation to thermodynamics;
describe how a heat engine and refrigerator work;
draw and interpret PV diagrams, including calculating the work done by a system;
describe isothermal and adiabatic processes and provide examples of each; and
calculate the Carnot efficiency of a heat engine and explain why it can never be 100%.

25A: Heat engines

733Systems and processes
734The zeroth and first laws of thermodynamics
735The second law of thermodynamics
737What entropy means
738The third law and absolute zero
739Section 1 review
740Heat engines
741Converting heat into work
742PV diagrams
743Interpreting a PV diagram
744Efficiency of a heat engine
745Isothermal and adiabatic processes
746Carnot cycle
747Efficiency of a Carnot engine
74825A: Heat engines
750Section 2 review
751Chapter review
P V γ = constant
efficiency=( 1 T 1 T 2 )×100%
thermodynamicszeroth law of thermodynamicsfirst law of thermodynamics
entropysecond law of thermodynamicsreversibility
third law of thermodynamicsheat enginePV diagram
isothermal processadiabatic processCarnot cycle
Carnot efficiencyrefrigerator

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