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Halliday/Resnick/Walker Fundamentals of Physics

Halliday/Resnick/Walker Fundamentals of Physics. Classroom Response System Questions. Chapter 20 Entropy and the Second Law of Thermodynamics. Interactive Lecture Questions.

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Halliday/Resnick/Walker Fundamentals of Physics

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  1. Halliday/Resnick/WalkerFundamentals of Physics • Classroom Response System Questions Chapter 20 Entropy and the Second Law of Thermodynamics Interactive Lecture Questions

  2. 20.2.1. A leaf is growing on a tree. Does this growth process violate the second law of thermodynamics when it is stated in terms of entropy? a) Yes, but the law does not apply to living things. It only applies to inanimate objects. b) Yes, because this law is not applicable in situations involving radiant energy from the Sun. c) No, because the entropy of the Sun has decreased while the entropy of the leaf increases as it grows. d) No, because while the entropy of the leaf is decreasing as it grows, there is a net increase in entropy because of the light emitted from the leaf. e) No, because there is no net increase in the energy of the leaf.

  3. 20.2.1. A leaf is growing on a tree. Does this growth process violate the second law of thermodynamics when it is stated in terms of entropy? a) Yes, but the law does not apply to living things. It only applies to inanimate objects. b) Yes, because this law is not applicable in situations involving radiant energy from the Sun. c) No, because the entropy of the Sun has decreased while the entropy of the leaf increases as it grows. d) No, because while the entropy of the leaf is decreasing as it grows, there is a net increase in entropy because of the light emitted from the leaf. e) No, because there is no net increase in the energy of the leaf.

  4. 20.2.2. While watching a fantasy film, you observe a wizard wave his arms and six potion vials that had fallen to the floor suddenly piece themselves back together with the potions inside and rise up with a table. In the end, the table is upright and the six vials with their potions are sitting on the table as if nothing had happened. Which of the following principles or laws of physics is disobeyed by this scene from the movie? a) conservation of energy b) second law of thermodynamics c) Newton’s laws of motion d) time dilation e) the work-energy theorem

  5. 20.2.2. While watching a fantasy film, you observe a wizard wave his arms and six potion vials that had fallen to the floor suddenly piece themselves back together with the potions inside and rise up with a table. In the end, the table is upright and the six vials with their potions are sitting on the table as if nothing had happened. Which of the following principles or laws of physics is disobeyed by this scene from the movie? a) conservation of energy b) second law of thermodynamics c) Newton’s laws of motion d) time dilation e) the work-energy theorem

  6. 20.3.1. A box with five adiabatic sides contains an ideal gas with an initial temperature T0. The sixth side is diathermal and is placed in contact with a reservoir with a constant temperature T2 > T0. Assuming the specific heat capacity of the system does not change with temperature, why must the entropy change of the universe always be increasing as the box warms? a) Entropy will always be increasing since the work done on the gas in the box is negative. b) Entropy will always be increasing since the temperature of the box is always less than or equal to T2. c) Entropy will always be increasing since this process is reversible. d) Entropy will always be increasing since the temperature of the box is always greater than absolute zero. e) Entropy will always be increasing since in any process entropy increases.

  7. 20.3.1. A box with five adiabatic sides contains an ideal gas with an initial temperature T0. The sixth side is diathermal and is placed in contact with a reservoir with a constant temperature T2 > T0. Assuming the specific heat capacity of the system does not change with temperature, why must the entropy change of the universe always be increasing as the box warms? a) Entropy will always be increasing since the work done on the gas in the box is negative. b) Entropy will always be increasing since the temperature of the box is always less than or equal to T2. c) Entropy will always be increasing since this process is reversible. d) Entropy will always be increasing since the temperature of the box is always greater than absolute zero. e) Entropy will always be increasing since in any process entropy increases.

  8. 20.3.2. An ideal gas is compressed as it is held at constant temperature. Which one of the following statements concerning this situation is true? a) No work is done on the gas during this process. b) Heat is transferred out of the gas. c) The internal energy of the gas is constant during this process. d) Choices (a) and (b) are both correct. e) Choices (b) and (c) are both correct.

  9. 20.3.2. An ideal gas is compressed as it is held at constant temperature. Which one of the following statements concerning this situation is true? a) No work is done on the gas during this process. b) Heat is transferred out of the gas. c) The internal energy of the gas is constant during this process. d) Choices (a) and (b) are both correct. e) Choices (b) and (c) are both correct.

  10. 20.3.3. Two containers with thermally insulating walls are connected by a valve. One of the containers is completely evacuated; and the other is filled with an ideal gas. How does the temperature of the gas after the valve is opened and equal amounts of gas occupy both containers compare to the temperature of the gas before the valve was opened? a) The final temperature will be greater than the initial temperature. b) The final temperature will be less than the initial temperature. c) The final temperature will be the same as the initial temperature. d) This cannot be answered without knowing the initial volumes of the two containers. e) This cannot be answered without knowing the initial pressure of the gas.

  11. 20.3.3. Two containers with thermally insulating walls are connected by a valve. One of the containers is completely evacuated; and the other is filled with an ideal gas. How does the temperature of the gas after the valve is opened and equal amounts of gas occupy both containers compare to the temperature of the gas before the valve was opened? a) The final temperature will be greater than the initial temperature. b) The final temperature will be less than the initial temperature. c) The final temperature will be the same as the initial temperature. d) This cannot be answered without knowing the initial volumes of the two containers. e) This cannot be answered without knowing the initial pressure of the gas.

  12. 20.3.4. Which one of the following statements concerning the internal energy of a system is true? a) Thermal energy at a lower pressure can be considered “higher quality” energy because it can do more work than thermal energy at a higher pressure. b) Thermal energy at a lower temperature can be considered “higher quality” energy because it can do more work than thermal energy at a higher temperature. c) Thermal energy at a higher pressure can be considered “higher quality” energy because it can do more work than thermal energy at a lower pressure. d) Thermal energy at a higher temperature can be considered “higher quality” energy because it can do more work than thermal energy at a lower temperature. e) Thermal energy at a higher entropy can be considered “higher quality” energy because it can do more work than thermal energy at a lower entropy.

  13. 20.3.4. Which one of the following statements concerning the internal energy of a system is true? a) Thermal energy at a lower pressure can be considered “higher quality” energy because it can do more work than thermal energy at a higher pressure. b) Thermal energy at a lower temperature can be considered “higher quality” energy because it can do more work than thermal energy at a higher temperature. c) Thermal energy at a higher pressure can be considered “higher quality” energy because it can do more work than thermal energy at a lower pressure. d) Thermal energy at a higher temperature can be considered “higher quality” energy because it can do more work than thermal energy at a lower temperature. e) Thermal energy at a higher entropy can be considered “higher quality” energy because it can do more work than thermal energy at a lower entropy.

  14. 20.5.1. An automobile engine that burns gasoline has been engineered to have a relatively high efficiency of 22 %. While a car is being driven along a road on a long trip, 14 gallons of gasoline are consumed by the engine. Of the 14 gallons, how much gasoline was used in doing the work of propelling the car? a) 14 gallons b) about 11 gallons c) about 8 gallons d) about 3 gallons e) about 1 gallon

  15. 20.5.1. An automobile engine that burns gasoline has been engineered to have a relatively high efficiency of 22 %. While a car is being driven along a road on a long trip, 14 gallons of gasoline are consumed by the engine. Of the 14 gallons, how much gasoline was used in doing the work of propelling the car? a) 14 gallons b) about 11 gallons c) about 8 gallons d) about 3 gallons e) about 1 gallon

  16. 20.5.2. Consider the various paths shown on the pressure-volume graph. By following which of these paths, does the system do the most work? a) 1 to 2 to 4 b) 1 to 4 c) 1 to 3 to 4 d) Each of these paths results in the same amount of work done.

  17. 20.5.2. Consider the various paths shown on the pressure-volume graph. By following which of these paths, does the system do the most work? a) 1 to 2 to 4 b) 1 to 4 c) 1 to 3 to 4 d) Each of these paths results in the same amount of work done.

  18. 20.5.3. During the power stroke of an internal combustion engine, the air-fuel mixture is ignited and the expanding hot gases push on the piston. Fuel efficiency is maximized in this process when the ignited gas is as hot as possible, the gas expands allowing a maximum amount of work to be done, and cooled exhaust gas is released at the end of the cycle. Assuming the engine exhibits the highest efficiency possible, which of the following statements concerning the exhaust gas must be true to avoid violating the second law of thermodynamics? a) The exhaust gas must be hotter than the outside air temperature. b) The exhaust gas must be at the same pressure as the outside air. c) The exhaust gas must be cooled to the same temperature as the outside air. d) The exhaust gas must be cooled below the temperature of the outside air. e) Real engines will always violate the second law of thermodynamics.

  19. 20.5.3. During the power stroke of an internal combustion engine, the air-fuel mixture is ignited and the expanding hot gases push on the piston. Fuel efficiency is maximized in this process when the ignited gas is as hot as possible, the gas expands allowing a maximum amount of work to be done, and cooled exhaust gas is released at the end of the cycle. Assuming the engine exhibits the highest efficiency possible, which of the following statements concerning the exhaust gas must be true to avoid violating the second law of thermodynamics? a) The exhaust gas must be hotter than the outside air temperature. b) The exhaust gas must be at the same pressure as the outside air. c) The exhaust gas must be cooled to the same temperature as the outside air. d) The exhaust gas must be cooled below the temperature of the outside air. e) Real engines will always violate the second law of thermodynamics.

  20. 20.6.1. A house that is heated using a heat pump with an ideal coefficient of performance loses heat to its surroundings at a rate of Z1(ThouseTsurr.), where Z1 is a constant, Thouse is the temperature inside the house; and Tsurr. is the temperature of its surroundings. In this process, heat is taken from the surroundings and heats the house at a rate of Z2(ToutThouse) where Tout is the temperature of the air output from the heat pump, which has a constant value. Which one of the following expressions is equal to the efficiency of the heat pump? a) b) c) d) e)

  21. 20.6.1. A house that is heated using a heat pump with an ideal coefficient of performance loses heat to its surroundings at a rate of Z1(ThouseTsurr.), where Z1 is a constant, Thouse is the temperature inside the house; and Tsurr. is the temperature of its surroundings. In this process, heat is taken from the surroundings and heats the house at a rate of Z2(ToutThouse) where Tout is the temperature of the air output from the heat pump, which has a constant value. Which one of the following expressions is equal to the efficiency of the heat pump? a) b) c) d) e)

  22. 20.6.2. An air conditioner pumps heat from a cold room to the hot outdoors in a three step cyclic process: (1) Room temperature, low pressure refrigerant gas passes through a compressor and comes out with increased temperature and increased pressure. The hot gas passes through piping on the outside, where heat is rejected to the surroundings. (2) The gas then passes through a narrower pipe before entering a compressor. Work is done by the compressor to increase the pressure enough for the gas to turn into a liquid. (3) The liquid then undergoes free expansion into a gas and cools. The cool gas passes through pipes that are inside the house. The inside air is cooled by coming into contact with these pipes. The refrigerant gas exits these pipes as a room temperature, low pressure gas. The cycle is then repeated. Why doesn’t this system violate the second law of thermodynamics? a) The internal energy of the gas is constant. b) Heat is normally taken from a warm place and transported to a warmer place. c) The system involves a closed cycle. d) Work is continually done on the system. e) Since the compressor adds entropy, the total entropy increases.

  23. 20.6.2. An air conditioner pumps heat from a cold room to the hot outdoors in a three step cyclic process: (1) Room temperature, low pressure refrigerant gas passes through a compressor and comes out with increased temperature and increased pressure. The hot gas passes through piping on the outside, where heat is rejected to the surroundings. (2) The gas then passes through a narrower pipe before entering a compressor. Work is done by the compressor to increase the pressure enough for the gas to turn into a liquid. (3) The liquid then undergoes free expansion into a gas and cools. The cool gas passes through pipes that are inside the house. The inside air is cooled by coming into contact with these pipes. The refrigerant gas exits these pipes as a room temperature, low pressure gas. The cycle is then repeated. Why doesn’t this system violate the second law of thermodynamics? a) The internal energy of the gas is constant. b) Heat is normally taken from a warm place and transported to a warmer place. c) The system involves a closed cycle. d) Work is continually done on the system. e) Since the compressor adds entropy, the total entropy increases.

  24. 20.6.3. You are repairing a window-style air conditioner in a closed workroom. You succeed in getting it to work, but are called away soon after you turn it on. Unfortunately, you are unable to return for several hours to turn it off. Assuming that it was running as efficiently as possible while you were away, how has the temperature of the workroom changed in your absence? a) The room is somewhat cooler than before I left. b) The room is slightly cooler than before I left. c) The temperature of the room has not changed. d) The room is warmer than before I left. e) The air near the ceiling will be very warm, but the air around the air conditioner will be very cool.

  25. 20.6.3. You are repairing a window-style air conditioner in a closed workroom. You succeed in getting it to work, but are called away soon after you turn it on. Unfortunately, you are unable to return for several hours to turn it off. Assuming that it was running as efficiently as possible while you were away, how has the temperature of the workroom changed in your absence? a) The room is somewhat cooler than before I left. b) The room is slightly cooler than before I left. c) The temperature of the room has not changed. d) The room is warmer than before I left. e) The air near the ceiling will be very warm, but the air around the air conditioner will be very cool.

  26. 20.6.4. A tray of water is placed into a freezer. As the water cools, its entropy decreases and eventually it turns to ice. Why doesn’t this process violate the second law of thermodynamics? a) When the ice is later taken out and melted, the entropy will increase back to what it was before the tray was put into the freezer. b) The overall entropy increases due to the refrigerator chilling and eventually freezing the water. c) The entropy of the tray increases to offset the decrease in the entropy of the water. d) The entropy of the water decreases, but upon freezing it increases to its previous value. e) The process as described does violate the second law of thermodynamics.

  27. 20.6.4. A tray of water is placed into a freezer. As the water cools, its entropy decreases and eventually it turns to ice. Why doesn’t this process violate the second law of thermodynamics? a) When the ice is later taken out and melted, the entropy will increase back to what it was before the tray was put into the freezer. b) The overall entropy increases due to the refrigerator chilling and eventually freezing the water. c) The entropy of the tray increases to offset the decrease in the entropy of the water. d) The entropy of the water decreases, but upon freezing it increases to its previous value. e) The process as described does violate the second law of thermodynamics.

  28. 20.6.5. Consider the following diagram of a system representing your kitchen. You have just finished dinner and have placed the leftovers in the refrigerator. On the diagram, “R” represents the inner workings of the refrigeration unit, Q1 and Q2 represent heat that is being transferred, and W is an amount of work. “L” represents your leftovers. What are the correct directions for the arrows indicated by the numbers “1” and “2?” a) Arrow 1 points into the refrigerator and arrow 2 points out of the refrigerator. b) Arrow 1 points out of the refrigerator and arrow 2 points into the refrigerator. c) Arrow 1 points into the refrigerator and arrow 2 points into the refrigerator. d) Arrow 1 points out of the refrigerator and arrow 2 points out of the refrigerator.

  29. 20.6.5. Consider the following diagram of a system representing your kitchen. You have just finished dinner and have placed the leftovers in the refrigerator. On the diagram, “R” represents the inner workings of the refrigeration unit, Q1 and Q2 represent heat that is being transferred, and W is an amount of work. “L” represents your leftovers. What are the correct directions for the arrows indicated by the numbers “1” and “2?” a) Arrow 1 points into the refrigerator and arrow 2 points out of the refrigerator. b) Arrow 1 points out of the refrigerator and arrow 2 points into the refrigerator. c) Arrow 1 points into the refrigerator and arrow 2 points into the refrigerator. d) Arrow 1 points out of the refrigerator and arrow 2 points out of the refrigerator.

  30. 20.8.1. Which of the following properties applies to a microstate exhibiting a high degree of entropy? a) The microstate is at high temperature. b) The microstate has a larger probability of being occupied than other microstates. c) The microstate is at low temperature. d) The microstate is at high pressure. e) The state is one with a larger number of microstates than other states that have less entropy.

  31. 20.8.1. Which of the following properties applies to a microstate exhibiting a high degree of entropy? a) The microstate is at high temperature. b) The microstate has a larger probability of being occupied than other microstates. c) The microstate is at low temperature. d) The microstate is at high pressure. e) The state is one with a larger number of microstates than other states that have less entropy.

  32. 20.8.2. Consider the dice shown as a simple model of a thermodynamic system. In this system, what corresponds to that microstates and what corresponds to the macrostates? a) The number on a die (e.g. 6 or 2) corresponds to a microstate; and the numbers on all the dice (1, 2, 4, 6) correspond to the macrostate. b) The number on a die (e.g. 6 or 2) corresponds to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. c) The numbers on all the dice {1, 2, 4, 6} correspond to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. d) The sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to a microstate; and the numbers on all the dice {1, 2, 4, 6} correspond to the macrostate.

  33. 20.8.2. Consider the dice shown as a simple model of a thermodynamic system. In this system, what corresponds to that microstates and what corresponds to the macrostates? a) The number on a die (e.g. 6 or 2) corresponds to a microstate; and the numbers on all the dice (1, 2, 4, 6) correspond to the macrostate. b) The number on a die (e.g. 6 or 2) corresponds to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. c) The numbers on all the dice {1, 2, 4, 6} correspond to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. d) The sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to a microstate; and the numbers on all the dice {1, 2, 4, 6} correspond to the macrostate.

  34. 20.8.3. Consider the dice shown as a simple model of a thermodynamic system. In this system, the numbers on all the dice {1, 2, 4, 6} correspond to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. Which one of the following microstates is the least likely to occur? a) {6, 1, 6, 1} b) {1, 1, 1, 1} c) {2, 5, 1, 4} d) {2, 2, 4, 4} e) All microstates are equally likely.

  35. 20.8.3. Consider the dice shown as a simple model of a thermodynamic system. In this system, the numbers on all the dice {1, 2, 4, 6} correspond to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. Which one of the following microstates is the least likely to occur? a) {6, 1, 6, 1} b) {1, 1, 1, 1} c) {2, 5, 1, 4} d) {2, 2, 4, 4} e) All microstates are equally likely.

  36. 20.8.4. Consider the dice shown as a simple model of a thermodynamic system. In this system, the numbers on all the dice {1, 2, 4, 6} correspond to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. Which one of the following macrostates is the least likely to occur? a) 4 b) 16 c) 10 d) 8 e) All macrostates are equally likely.

  37. 20.8.4. Consider the dice shown as a simple model of a thermodynamic system. In this system, the numbers on all the dice {1, 2, 4, 6} correspond to a microstate; and the sum of the numbers on all the dice (1 + 2 + 4 + 6 = 13) corresponds to the macrostate. Which one of the following macrostates is the least likely to occur? a) 4 b) 16 c) 10 d) 8 e) All macrostates are equally likely.

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