Active Figure 22. 10 The Carnot cycle Active Figure 22.10  The Carnot cycle. (a) In process AB, the gas expands isothermally while in contact with a reservoir at Th. (b) In process BC, the gas expands adiabatically (Q = 0). (c) In process CD, the gas is compressed isothermally while in contact with a reservoir at Tc < Th. (d) In process DA, the gas is compressed adiabatically. The arrows on the piston indicate the direction of its motion during each process. At the Active Figures link at http://www.pse6.com, you can observe the motion of the piston in the Carnot cycle while you also observe the cycle on the PV diagram of Figure 22.11. Fig. 22.10, p.676

Active Figure 22. 11 PV diagram for the Carnot cycle Active Figure 22.11  PV diagram for the Carnot cycle. The net work done Weng equals the net energy transferred into the Carnot engine in one cycle, |Qh| – |Qc|. Note that ∆Eint = 0 for the cycle. At the Active Figures link at http://www.pse6.com, you can observe the Carnot cycle on the PV diagram while you also observe the motion of the piston in Figure 22.10. Fig. 22.11, p.676

Active Figure 22.12  The four-stroke cycle of a conventional gasoline engine. The arrows on the piston indicate the direction of its motion during each process. (a) In the intake stroke, air and fuel enter the cylinder. (b) The intake valve is then closed, and the air–fuel mixture is compressed by the piston. (c) The mixture is ignited by the spark plug, with the result that the temperature of the mixture increases at essentially constant volume. (d) In the power stroke, the gas expands against the piston. (e) Finally, the residual gases are expelled, and the cycle repeats. At the Active Figures link at http://www.pse6.com, you can observe the motion of the piston and crankshaft while you also observe the cycle on the PV diagram of Figure 22.13. Fig. 22.12, p.679

Active Figure 22.13  PV diagram for the Otto cycle, which approximately represents the processes occurring in an internal combustion engine. At the Active Figures link at http://www.pse6.com, you can observe the Otto cycle on the PV diagram while you observe the motion of the piston and crankshaft in Figure 22.12. Fig. 22.13, p.679

Active Figure 22.13  PV diagram for the Otto cycle, which approximately represents the processes occurring in an internal combustion engine. At the Active Figures link at http://www.pse6.com, you can observe the Otto cycle on the PV diagram while you observe the motion of the piston and crankshaft in Figure 22.12. Fig. 22.13, p.679

Figure 22.14  PV diagram for an ideal diesel engine. Fig. 22.14, p.681

Figure 22.15 (a) A royal flush is a highly ordered poker hand with low probability of occurring. (b) A disordered and worthless poker hand. The probability of this particular hand occurring is the same as that of the royal flush. There are so many worthless hands, however, that the probability of being dealt a worthless hand is much higher than that of a royal flush.

Figure 22.17  In a free expansion, the gas is allowed to expand into a region that was previously evacuated. Fig. 22.17, p.690

Active Figure 22. 2 Schematic representation of a heat engine Active Figure 22.2  Schematic representation of a heat engine. The engine does work Weng. The arrow at the top represents energy Qh > 0 entering the engine. At the bottom, Qc < 0 represents energy leaving the engine. At the Active Figures link at http://www.pse6.com, you can select the efficiency of the engine and observe the transfer of energy. Fig. 22.1, p.669

Figure 22.4  Schematic diagram of a heat engine that takes in energy from a hot reservoir and does an equivalent amount of work. It is impossible to construct such a perfect engine. Fig. 22.4, p.670

Active Figure 22.5  Schematic diagram of a heat pump, which takes in energy Qc > 0 from a cold reservoir and expels energy Qh < 0 to a hot reservoir. Work W is done on the heat pump. A refrigerator works the same way. At the Active Figures link at http://www.pse6.com, you can select the COP of the heat pump and observe the transfer of energy. Fig. 22.5, p.671

Figure 22.6  Schematic diagram of an impossible heat pump or refrigerator—that is, one that takes in energy from a cold reservoir and expels an equivalent amount of energy to a hot reservoir without the input of energy by work. Fig. 22.6, p.672

Figure 22.7 The coils on the back of a refrigerator transfer energy by heat to the air. The second law of thermodynamics states that this amount of energy must be greater than the amount of energy removed from the contents of the refrigerator, due to the input of energy by work. (Charles D. Winters) Fig. 22.7, p.672

Figure 22. 16 Adiabatic free expansion of a gas Figure 22.16  Adiabatic free expansion of a gas. When the membrane separating the gas from the evacuated region is ruptured, the gas expands freely and irreversibly. As a result, it occupies a greater final volume. The container is thermally insulated from its surroundings; thus, Q = 0. Fig. 22.16, p.688

Figure 22.17  In a free expansion, the gas is allowed to expand into a region that was previously evacuated. Fig. 22.17a, p.690

Figure 22.17  In a free expansion, the gas is allowed to expand into a region that was previously evacuated. Fig. 22.17b, p.690

Figure 22.18  By tossing a coin into a jar, the carnival-goer can win the fish in the jar. It is more likely that the coin will land in a jar containing a goldfish than in the one containing the black fish. Fig. 22.18, p.691

Active Figure 22.19 (a) One molecule in a two-sided container has a 1-in-2 chance of being on the left side. (b) Two molecules have a 1-in-4 chance of being on the left side at the same time. (c) Three molecules have a 1-in-8 chance of being on the left side at the same time. At the Active Figures link at http://www.pse6.com, you can choose the number of molecules to put in the container and measure the probability of all of them being in the left hand side. Fig. 22.19, p.692

Table 22.1, p.693

Figure 22.20 A gas expands to four times its initial volume and back to the initial temperature by means of a two-step process. Fig. 22.20, p.693

Fig. Q22.11, p.695

Fig. P22.26, p.698

Fig. P22.45, p.699

Fig. P22.46, p.699

Fig. P22.57, p.700

Fig. P22.62, p.701

Fig. P22.65, p.701

Figure 22.3  PV diagram for an arbitrary cyclic process taking place in an engine. The value of the net work done by the engine in one cycle equals the area enclosed by the curve. Fig. 22.3, p.670

Figure 22.8  Adiabatic free expansion of a gas. Fig. 22.8, p.674

Figure 22.9  A gas in thermal contact with an energy reservoir is compressed slowly as individual grains of sand drop onto the piston. The compression is isothermal and reversible. Fig. 22.9, p.674