College Physics
10th Edition
ISBN: 9781285737027
Author: Raymond A. Serway, Chris Vuille
Publisher: Cengage Learning
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Textbook Question
Chapter 12, Problem 40P
Suppose an ideal (Carnot) heal pump could be constructed, (a) Using Equation 12.15, obtain an expression for the coefficient of performance for such a heat pump in terms of Th and Tc. (b) Would such a heal pump work better If the difference in the operating temperatures were greater or smaller? (c) Compute the coefficient of performance for such a heat pump if the cold reservoir is 50.0°C and indoor temperature is 70.0°C.
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Chapter 12 Solutions
College Physics
Ch. 12.1 - By visual inspection, order the PV diagrams shown...Ch. 12.4 - Three engines operate between reservoirs separated...Ch. 12.5 - Which of the following is true for the entropy...Ch. 12.5 - Prob. 12.5QQCh. 12 - Prob. 3CQCh. 12 - Prob. 4CQCh. 12 - For an ideal gas in an isothermal process, there...Ch. 12 - Is it possible to construct a heat engine that...Ch. 12 - When a sealed Thermos bottle full of hot coffee is...Ch. 12 - The first law of thermodynamics says we cant get...
Ch. 12 - Prob. 13CQCh. 12 - Prob. 14CQCh. 12 - An ideal gas is compressed to half its initial...Ch. 12 - A thermodynamic process occurs in which the...Ch. 12 - Prob. 17CQCh. 12 - An ideal gas is enclosed in a cylinder with a...Ch. 12 - Sketch a PV diagram and find the work done by the...Ch. 12 - Gas in a container is at a pressure of 1.5 atm and...Ch. 12 - A 40.0-g projectile is launched by the expansion...Ch. 12 - A gas expands from I to F along the three paths...Ch. 12 - Sketch a PV diagram of the following processes:...Ch. 12 - A sample of helium behaves as an ideal gas as it...Ch. 12 - (a) Find the work done by an ideal gas as it...Ch. 12 - One mole of an ideal gas initially at a...Ch. 12 - (a) Determine the work done on a fluid that...Ch. 12 - Prob. 11PCh. 12 - A cylinder of volume 0.300 m3 contains 10.0 mol of...Ch. 12 - A gas expands from I to F in Figure P12.5. The...Ch. 12 - In a running event, a sprinter does 4.8 105 J of...Ch. 12 - A gas is compressed at a constant pressure of...Ch. 12 - A quantity of a monatomic ideal gas undergoes a...Ch. 12 - A gas is enclosed in a container fitted with a...Ch. 12 - A monatomic ideal gas under-goes the thermodynamic...Ch. 12 - An ideal gas is compressed from a volume of Vi =...Ch. 12 - A system consisting of 0.025 6 moles of a diatomic...Ch. 12 - An ideal monatomic gas expands isothermally from...Ch. 12 - An ideal gas expands at constant pressure. (a)...Ch. 12 - An ideal monatomic gas is contained in a vessel of...Ch. 12 - Consider the cyclic process described by Figure...Ch. 12 - A 5.0-kg block of aluminum is heated from 20C to...Ch. 12 - One mole of gas initially at a pressure of 2.00...Ch. 12 - Consider the Universe to be an adiabatic expansion...Ch. 12 - Suppose the Universe is considered to be an ideal...Ch. 12 - A gas increases in pressure from 2.00 atm to 6.00...Ch. 12 - An ideal gas expands at a constant pressure of...Ch. 12 - A heat engine operates between a reservoir at 25C...Ch. 12 - A heat engine is being designed to have a Carnot...Ch. 12 - The work done by an engine equals one-fourth the...Ch. 12 - In each cycle of its operation, a heat engine...Ch. 12 - One of the most efficient engines ever built is a...Ch. 12 - A gun is a heat engine. In particular, it is an...Ch. 12 - An engine absorbs 1.70 kJ from a hot reservoir at...Ch. 12 - A heat pump has a coefficient of performance of...Ch. 12 - A freezer has a coefficient of performance of...Ch. 12 - Suppose an ideal (Carnot) heal pump could be...Ch. 12 - In one cycle a heat engine absorbs 500 J from a...Ch. 12 - A power plant has been proposed that would make...Ch. 12 - Prob. 43PCh. 12 - A heat engine operates in a Carnot cycle between...Ch. 12 - A Styrofoam cup holding 125 g of hot water at 1.00...Ch. 12 - A 65-g ice cube is initially at 0.0C. (a) Find the...Ch. 12 - A freezer is used to freeze 1.0 L of water...Ch. 12 - What is the change in entropy of 1.00 kg of liquid...Ch. 12 - A 70.0-kg log falls from a height of 25.0 m into a...Ch. 12 - Prob. 50PCh. 12 - Prob. 51PCh. 12 - When an aluminum bar is temporarily connected...Ch. 12 - Prepare a table like Table 12.3 for the following...Ch. 12 - Prob. 54PCh. 12 - Prob. 55PCh. 12 - Prob. 56PCh. 12 - Sweating is one of the main mechanisms with which...Ch. 12 - A Carnot engine operates between the temperatures...Ch. 12 - Prob. 59APCh. 12 - A Carnot engine operates between 100C and 20C. How...Ch. 12 - A substance undergoes the cyclic process shown in...Ch. 12 - When a gas follows path 123 on the PV diagram in...Ch. 12 - Prob. 63APCh. 12 - An ideal gas initially at pressure P0, volume V0,...Ch. 12 - One mole of neon gas is heated from 300. K to 420....Ch. 12 - Every second at Niagara Falls, approximately 5.00 ...Ch. 12 - A cylinder containing 10.0 moles of a monatomic...Ch. 12 - Prob. 68APCh. 12 - Suppose you spend 30.0 minutes on a stair-climbing...Ch. 12 - Hydrothermal vents deep on the ocean floor spout...Ch. 12 - An electrical power plant has an overall...Ch. 12 - A diatomic ideal gas expands from a volume of VA =...
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- Suppose you want to operate an ideal refrigerator with a cold temperature of 10.0C, and you would like it to have a coefficient of performance 7.00. What is the hot reservoir temperature for such a refrigerator?arrow_forwardAn ideal heat pump is being considered for use in heating an environment with a temperature of 22.0C. What is the cold reservoir temperature if the pump is to have a coefficient of performance of 12.0?arrow_forwardUse a PV diagram such as the one in Figure 22.2 (page 653) to figure out how you could modify an engine to increase the work done.arrow_forward
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- A Carnot engine has an efficiency of 0.60. When the temperature of its cold reservoir the efficiency drops to 0.55. If initially Tc=27, determine (a) the constant value of Th and (b) the final value of Tc.arrow_forwardConsider the cyclic process depicted in Figure P17.28. If Q is negative for the process BC and Eint is negative for the process CA, what are the signs of Q, W, and Eint that are associated with each of the three processes?arrow_forwardAn ideal Otto cycle has a compression ratio of 8. At the beginning of the compression process, air is at 95 kPa and 27C, and 750 kJ/kg of heat is transferred to air during the constant-volume heat-addition process. Taking into account the variation of specific heats with temperature, determine (a) the pressure and temperature at the end of the heat- addition process, (b) the net work output, (c) the thermal efficiency, and (d) the mean effective pressure for the cycle.arrow_forward
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