Thermodynamics is the study of processes in which energy is transferred
as heat and as work. Often, we refer to a specific system when talking about thermodynamics; the surrounding components are called the environment. When talking about thermodynamics, two important laws come to mind. They are the first and second laws of thermodynamics, which talk about thermodynamic processes, heat engines, heat pumps, entropy, and more. Before reading about the specifics of thermodynamics, please take a look at the objectives and amount of material covered on the actual AP Physics B Exam:
Objectives and Percentage on Exam
Kinetic theory and thermodynamics 7%
1. Ideal gases
a. Kinetic model
b. Ideal gas law
2. Laws of thermodynamics
a. First law (including processes on pV diagrams)
b. Second law (including heat engines)
1. Ideal gases
a. Kinetic model
b. Ideal gas law
2. Laws of thermodynamics
a. First law (including processes on pV diagrams)
b. Second law (including heat engines)
Laws of Thermodynamics
a) Students should know how to apply the first law of thermodynamics so they can:
(1) Relate the heat absorbed by a gas, the work performed by the gas, and the internal energy change of the gas for any of the processes above.
(2) Relate the work performed by a gas in a cyclic process to the area enclosed by a curve on a pV diagram.
b) Students should understand the second law of thermodynamics, the concept of entropy, and heat engines and the Carnot cycle so they can:
(1) Determine whether entropy will increase, decrease, or stay the same during a particular situation.
(2) Compute the maximum possible efficiency of a heat engine operating between two given temperatures.
(3) Compute the actual efficiency of a heat engine.
(4) Relate the heats exchanged at each thermal reservoir in a Carnot cycle to the temperatures of the reservoirs.
a) Students should know how to apply the first law of thermodynamics so they can:
(1) Relate the heat absorbed by a gas, the work performed by the gas, and the internal energy change of the gas for any of the processes above.
(2) Relate the work performed by a gas in a cyclic process to the area enclosed by a curve on a pV diagram.
b) Students should understand the second law of thermodynamics, the concept of entropy, and heat engines and the Carnot cycle so they can:
(1) Determine whether entropy will increase, decrease, or stay the same during a particular situation.
(2) Compute the maximum possible efficiency of a heat engine operating between two given temperatures.
(3) Compute the actual efficiency of a heat engine.
(4) Relate the heats exchanged at each thermal reservoir in a Carnot cycle to the temperatures of the reservoirs.
Graphic Organizer
Below is a graphic organizer of all the major concepts covered in this chapter. Please view with 100% magnification for the best view.