Mastering Physics with Pearson eText -- Standalone Access Card -- for University Physics with Modern Physics (14th Edition)
14th Edition
ISBN: 9780133978216
Author: Hugh D. Young, Roger A. Freedman
Publisher: PEARSON
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Textbook Question
Chapter 20, Problem 20.5DQ
Why must a room air conditioner be placed in a window rather than just set on the floor and plugged in? Why can a refrigerator be set on the floor and plugged in?
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(a) energy per cycle is delivered as heat to the room and (b) work
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Chapter 20 Solutions
Mastering Physics with Pearson eText -- Standalone Access Card -- for University Physics with Modern Physics (14th Edition)
Ch. 20.1 - Your left and right hands are normally at the same...Ch. 20.2 - Rank the following heat engines in order from...Ch. 20.3 - For an Otto-cycle engine with cylinders of a fixed...Ch. 20.4 - Can you cool your house by leaving the...Ch. 20.5 - Would a 100%-efficient engine (Fig. 20.11a)...Ch. 20.6 - An inventor looking for financial support comes to...Ch. 20.7 - Suppose 2.00 kg of water at 50C spontaneously...Ch. 20.8 - A quantity of N molecules of an ideal gas...Ch. 20 - A pot is half-filled with water, and a lid is...Ch. 20 - Prob. 20.2DQ
Ch. 20 - Prob. 20.3DQCh. 20 - Prob. 20.4DQCh. 20 - Why must a room air conditioner be placed in a...Ch. 20 - Prob. 20.6DQCh. 20 - Prob. 20.7DQCh. 20 - An electric motor has its shaft coupled to that of...Ch. 20 - When a wet cloth is hung up in a hot wind in the...Ch. 20 - Compare the pV-diagram for the Otto cycle in Fig....Ch. 20 - The efficiency of heat engines is high when the...Ch. 20 - What would be the efficiency of a Carnot engine...Ch. 20 - Real heat engines, like the gasoline engine in a...Ch. 20 - Does a refrigerator full of food consume more...Ch. 20 - In Example 20.4, a Carnot refrigerator requires a...Ch. 20 - How can the thermal conduction of heat from a hot...Ch. 20 - Explain why each of the following processes is an...Ch. 20 - The free expansion of an ideal gas is an adiabatic...Ch. 20 - Are the earth and sun in thermal equilibrium? Are...Ch. 20 - Prob. 20.20DQCh. 20 - Prob. 20.21DQCh. 20 - Prob. 20.22DQCh. 20 - BIO A growing plant creates a highly complex and...Ch. 20 - A diesel engine performs 2200 J of mechanical work...Ch. 20 - An aircraft engine takes in 9000 J of heat and...Ch. 20 - A Gasoline Engine. A gasoline engine takes in 1.61...Ch. 20 - A gasoline engine has a power output of 180 kW...Ch. 20 - The pV-diagram in Fig. E20.5 shows a cycle of heat...Ch. 20 - (a) Calculate the theoretical efficiency for an...Ch. 20 - The Otto-cycle engine in a Mercedes-Benz SL1 a...Ch. 20 - Section 20.4 Refrigerators 20.8The coefficient of...Ch. 20 - A refrigerator has a coefficient of performance of...Ch. 20 - A freezer has a coefficient of performance of...Ch. 20 - A refrigerator has a coefficient of performance of...Ch. 20 - A Carnot engine is operated between two heat...Ch. 20 - A Carnot engine whose high-temperature reservoir...Ch. 20 - An ice-making machine operates in a Carnot cycle....Ch. 20 - A Carnot engine has an efficiency of 66% and...Ch. 20 - A certain brand of freezer is advertised to use...Ch. 20 - A Carnot refrigerator is operated between two heat...Ch. 20 - A Carnot heat engine uses a hot reservoir...Ch. 20 - You design an engine that takes in 1.50 104 J of...Ch. 20 - A 4.50-kg block of ice at 0.00C falls into the...Ch. 20 - A sophomore with nothing better to do adds heat to...Ch. 20 - CALC You decide to take a nice hot bath but...Ch. 20 - A 15.0-kg block of ice at 0.0C melts to liquid...Ch. 20 - CALC You make tea with 0.250 kg of 85.0C water and...Ch. 20 - Three moles of an ideal gas undergo a reversible...Ch. 20 - What is the change in entropy of 0.130 kg of...Ch. 20 - (a) Calculate the change in entropy when 1.00 kg...Ch. 20 - Entropy Change Due to Driving. Premium gasoline...Ch. 20 - CALC Two moles of an ideal gas occupy a volume V....Ch. 20 - A box is separated by a partition into two parts...Ch. 20 - CALC A lonely party balloon with a volume of 2.40...Ch. 20 - You are designing a Carnot engine that has 2 mol...Ch. 20 - CP An ideal Carnot engine operates between 500C...Ch. 20 - Prob. 20.34PCh. 20 - CP A certain heat engine operating on a Carnot...Ch. 20 - A heat engine takes 0.350 mol of a diatomic ideal...Ch. 20 - Prob. 20.37PCh. 20 - What is the thermal efficiency of an engine that...Ch. 20 - CALC You build a heal engine that takes 1.00 mol...Ch. 20 - CP As a budding mechanical engineer, you are...Ch. 20 - CALC A heal engine Operates using the cycle shown...Ch. 20 - CP BIO Humun Entropy. A person who has skin of...Ch. 20 - An experimental power plant at the Natural Energy...Ch. 20 - CP BIO A Human Engine. You decide to use your body...Ch. 20 - CALC A cylinder contains oxygen at a pressure of...Ch. 20 - A monatomic ideal gas it taken around the cycle...Ch. 20 - A Carnot engine operates between two heat...Ch. 20 - A typical coal-fired power plant generates 1000 MW...Ch. 20 - Automotive Thermodynamics. A Volkswagen Passat has...Ch. 20 - An air conditioner operates on 800 W of power and...Ch. 20 - The pV-diagram in Fig. P20.51 shows the cycle for...Ch. 20 - BIO Human Entropy. A person with skin of surface...Ch. 20 - CALC An object of mass m1, specific heat c1, and...Ch. 20 - CALC To heat 1 cup of water (250 cm3) to make...Ch. 20 - DATA In your summer job with a venture capital...Ch. 20 - DATA For a refrigerator or air conditioner, the...Ch. 20 - DATA You are conducting experiments to study...Ch. 20 - Consider a Diesel cycle that starts (at point a in...Ch. 20 - POWER FROM THE SEA. Ocean thermal energy...Ch. 20 - POWER FROM THE SEA. Ocean thermal energy...Ch. 20 - POWER FROM THE SEA. Ocean thermal energy...Ch. 20 - POWER FROM THE SEA. Ocean thermal energy...
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- A 1200-W electric resistance heating element whose diameter is 0.5 cm is immersed in 40 kg of water initially at 20C. Assuming the water container is well-insulated, determine how long it will take for this heater to raise the water temperature to 50C. Also, determine the entropy generated during this process, in kJ/K.arrow_forwardAssume that the turbines at a coal-powered power plant were upgraded resulting in an improvement in efficiency of 3.14%. Assume that prior to the upgrade the power station had an efficiency of 38%, and that the heat transfer into the engine in one day is still the same at 2.63 x 1014 J. (a) How much more electrical power is produced due to the upgrade? 95581 v kW (b) How much less heat transfer occurs to the environment due to the upgrade? 800000000000c x Jarrow_forwardAn engine with an efficiency of 0.30 absorbs 500 J of heat per cycle. (a) How much work does it perform per cycle? (b) How much heat does it discharge per cycle?arrow_forward
- An engine absorbs three times as much heat as it discharges. The work done by the engine per cycle is 50 J. Calculate (a) the efficiency of the engine, (b) the heat absorbed per cycle, and (c) the heat discharged per cycle.arrow_forwardAre the entropy changes of the system in the following processes positive or negative? (a) water vapor that condenses on a cold surface; (b) gas in a that leaks into the surrounding atmosphere; (c) an ice cube that melts in a glass of lukewarm water; (d)the lukewarm water of part (c); a real heat engine performing a cycle; (f) food cooled in a refrigerator.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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