College Physics
1st Edition
ISBN: 9781938168000
Author: Paul Peter Urone, Roger Hinrichs
Publisher: OpenStax College
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 15, Problem 64PE
In an air conditioner, 12.65 MJ of
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
In an air conditioner, 12.65 MJ of heat transfer occurs from a cold environment in 1.00 h. (a) What mass of ice melting would involve the same heat transfer? (b) How many hours of operation would be equivalent to melting 900 kg ofice? (c) If ice costs 20 cents per kg, do you think the air conditioner could be operated more cheaply than by simply using ice? Describe in detail how you evaluate the relative costs.
Consider the thermodynamic process, A->B->C->A shown above. The heat absorbed during A->B is 591J. If the change in internal energy during B->C is 4146J, What is the change in internal energy in SI units during C->A? Express only the number of your answer with 4 significant figures.
A 4-ton air conditioner removes 5.06×107 J (48,000 British thermal units) from a cold environment in 1.00 h. (a) What energy input in joules is necessary to do this if the air conditioner has an energy efficiency rating ( EER ) of 12.0?
(b) What is the cost of doing this if the work costs 10.0 cents per 3.60×106J (one kilowatt-hour)? (c) Discuss whether this cost seems realistic. Note that the energy efficiency rating ( EER ) of an air conditioner or refrigerator is defined to be the number of British thermal units of heat transfer from a cold environment per hour divided by the watts of power input.
Chapter 15 Solutions
College Physics
Ch. 15 - Describe the photo of the tea kettle at the...Ch. 15 - The first law of thermodynamics and the...Ch. 15 - Heat transfer Q and work done W are always energy...Ch. 15 - How do heat transfer and internal energy differ?...Ch. 15 - If you run down some stairs and stop, what happens...Ch. 15 - Give an explanation of how food energy (calories)...Ch. 15 - Identify the type of energy transferred to your...Ch. 15 - A great deal of effort time, and money has been...Ch. 15 - One method of converting heat transfer to doing...Ch. 15 - Would the previous question make any sense for an...
Ch. 15 - We ordinarily say that U=0 for an isothermal...Ch. 15 - The temperature of a rapidly expanding gas...Ch. 15 - Which cyclical process represented by the two...Ch. 15 - A real process may be nearly adiabatic if it...Ch. 15 - It is unlikely that a process can be isothermal...Ch. 15 - Imagine you are driving a car up Pike’s Peak in...Ch. 15 - Is a temperature difference necessary to operate a...Ch. 15 - Definitions of efficiency vary depending on how...Ch. 15 - Whyother than the fact that the second law of...Ch. 15 - Think about the drinking bird at the beginning of...Ch. 15 - Can improved engineering and materials be employed...Ch. 15 - Does the second law of thermodynamics alter the...Ch. 15 - Explain why heat pumps do not work as well in very...Ch. 15 - In some Northern European nations, homes are being...Ch. 15 - Why do refrigerators, air conditioners, and heat...Ch. 15 - Grocery store managers contend that there is less...Ch. 15 - Can you cool a kitchen by leaving the refrigerator...Ch. 15 - A woman shuts her summer cottage up in September...Ch. 15 - Consider a system with a certain energy content,...Ch. 15 - Does a gas become more orderly when it liquefies?...Ch. 15 - Explain how water’s entropy can decrease when it...Ch. 15 - Is a uniform-temperature gas more or less orderly...Ch. 15 - Give an example of a spontaneous process in which...Ch. 15 - What is the change in entropy in an adiabatic...Ch. 15 - Does the entropy at a star increase or decrease as...Ch. 15 - Explain why a building made of bricks has smaller...Ch. 15 - Explain why a building made of bricks has smaller...Ch. 15 - What is the change in internal energy of a car if...Ch. 15 - How much heat transfer occurs from a system, if...Ch. 15 - A system does 1.80108J of work while 7.50108J of...Ch. 15 - What is the change in internal energy of a system...Ch. 15 - Suppose a woman does 500 J of work and 9500 J of...Ch. 15 - (a) How much food energy will a man metabolize in...Ch. 15 - (a) What is the average metabolic rate in watts of...Ch. 15 - (a) How long will the energy in a 1470kJ (350kcal)...Ch. 15 - (a) A woman climbing the Washington Monument...Ch. 15 - A car tire contains 0.0380m3 S of air at a...Ch. 15 - A heliumfilled toy balloon has a gauge pressure of...Ch. 15 - Steam to drive an old—fashioned steam locomotive...Ch. 15 - A hand—driven tire pump has a piston with a 2.50cm...Ch. 15 - Calculate the net work output of a heat engine...Ch. 15 - What is the net work output of a heat engine that...Ch. 15 - Unreasonable Results What is wrong with the claim...Ch. 15 - (a) A cyclical heat engine, operating between...Ch. 15 - Construct Your Own Problem Consider a car's...Ch. 15 - Construct Your Own Problem Consider a car trip...Ch. 15 - A certain heat engine does 10.0 kJ of work and...Ch. 15 - With 2.56106J of heat transfer into this engine, a...Ch. 15 - (a) What is the work output of a cyclical heat...Ch. 15 - (a) What is the eficiency of a cyclical heat...Ch. 15 - The engine of a large Ship does 2.00108J of work...Ch. 15 - (a) How much heat transfer occurs to the...Ch. 15 - Assume that the turbines at a coal—powered power...Ch. 15 - This problem compares the energy output and heat...Ch. 15 - A certain gasoline engine has an efficiency of...Ch. 15 - A gascooled nuclear reactor operates between hot...Ch. 15 - (a) What is the hot reservoir temperature of a...Ch. 15 - Steam locomotives have an efficiency of 17.0% and...Ch. 15 - Practical steam engines utilize 450C steam, which...Ch. 15 - A coalfired electrical power station has an...Ch. 15 - Would you be willing to financially back an...Ch. 15 - Unreasonable Results (a) Suppose you want to...Ch. 15 - Unreasonable Results Calculate the cold reservoir...Ch. 15 - What is the coefficient of performance of an ideal...Ch. 15 - Suppose you have an ideal refrigerator that cools...Ch. 15 - What is the best coefficient of performance...Ch. 15 - In a very mild winter climate, a heat pump has...Ch. 15 - (a) What is the best coefficient of performance...Ch. 15 - (a) What is the best coefficient of performance...Ch. 15 - Suppose you want to operate an ideal refrigerator...Ch. 15 - An ideal heat pump is being considered for use in...Ch. 15 - A 4ton air conditioner removes 5.60107J (48,000...Ch. 15 - Show that the coefficients of performance of...Ch. 15 - (a) On a winter day, a certain house loses...Ch. 15 - On a hot summer day, 4.00106J of heat transfer...Ch. 15 - A hot rock ejected from a volcano's lava fountain...Ch. 15 - When 1.60105J of heat transfer occurs into a meat...Ch. 15 - The Sun radiates energy at the rate of 3.801026W...Ch. 15 - (a) In reaching equilibrium, how much heat...Ch. 15 - What is the decrease in entropy of 25.0 g of water...Ch. 15 - Find the increase in entropy of 1.00 kg of liquid...Ch. 15 - A large electrical power station generates 1000 MW...Ch. 15 - (a) How much heat transfer occurs from 20.0 kg of...Ch. 15 - Using Table 15.4, verify the contention that if...Ch. 15 - What percent of the time will you get something in...Ch. 15 - (a) If tossing 100 coins, how many ways...Ch. 15 - (a) What is the change in entropy if you start...Ch. 15 - (a) What is the change in entropy if you start...Ch. 15 - (a) If you toss 10 coins, what percent of the time...Ch. 15 - (a) Construct a table showing the macro states and...Ch. 15 - In an air conditioner, 12.65 MJ of heat transfer...
Additional Science Textbook Solutions
Find more solutions based on key concepts
4. When a smooth-flowing stream of water comes out of a faucet, it narrows as it falls. Why does it do this?
College Physics (10th Edition)
41. (II) A 12-cm-radius air duct is used to replenish the air of a room 8.2 m x 5.0 m x 3.5 m every 12 min. How...
Physics: Principles with Applications
(a) It is difficult to extinguish a fire on a crude oil tanker, because each liter of crude oil releases 2.8010...
University Physics Volume 2
1. a. Can a vector have nonzero magnitude if a component is zero? If no, why not? If yes, give an example.
b. C...
College Physics: A Strategic Approach (3rd Edition)
The electromagnetic spectrum of light is often arranged in terms of frequency. Which one of the following has t...
Lecture- Tutorials for Introductory Astronomy
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- An electrical power station uses 1.58 x 10-4 J of heat input with an efficiency of 35.7%. (a) How much work is done? (b) How much waste heat is produced by the station? (c) What is the ratio of waste heat to work output? waste heat work outputarrow_forwardConverting sunlight to electricity with solar cells has an efficiency of ≈15,. It’s possible to achieve a higher efficiency (though currently at higher cost) by using concentrated sunlight as the hot reservoir of a heat engine. Each dish as shown concentrates sunlight on one side of a heat engine, producing a hotreservoir temperature of 650°C. The cold reservoir, ambient air, is approximately 30°C. The actual working efficiency of this device is ≈30,. What is the theoretical maximum efficiency?arrow_forwardA 361-W heat pump operates between the ground, whose temperature is 6.2, and the interior of a house at 20.1. What is the theoretical maximum amount of heat per hour that the heat pump can supply to the house? Express your answer in MJ, to at least one digit after the decimal point.arrow_forward
- Many decisions are made on the basis of the payback period: the time it will take through savings to equal the capital cost of an investment. Acceptable payback times depend upon the business or philosophy one has. (For some industries, a payback period is as small as two years.) Suppose you wish to install the extra insulation. If energy cost $1.00 per million joules and the insulation was $4.00 per square meter, then calculate the simple payback time. Take the average for the 120 day heating season to be 15.0C.arrow_forwardAt a certain location, the solar power per unit area reaching Earth's surface is 200 W/ m^2, averaged over a 24-hour day. If the average power requirement in your home is 3 kW and you can convert solar power to electric power with 10 % efficiency, how large a collector area will you need to meet all your household energy requirements from solar energy? (Will a collector fit in your yard or on your roof? ).arrow_forwardAn electric heater transfers 9.20 ✕ 105 J into a block of ice with a mass of 2.35 kg and an initial temperature of 0°C. (a) How much of the energy (in J) supplied by the heater goes into melting all the ice into liquid water? (Enter your answer to at least three significant figures.) Review the definition of latent heat of fusion. How is the energy related to the mass and latent heat? J (b) How much of the energy (in J) supplied by the heater goes into raising the temperature of the liquid water? (Enter your answer to at least three significant figures.) Think about conservation of energy. The total energy supplied is known, and you found in part (a) the energy that goes into melting. How much is left over? J (c) What is the final temperature of the liquid water in degrees Celsius? °Carrow_forward
- Please answer the following question(s): 1. (a) What is the best coefficient of performance for a refrigerator that cools an environment at -28° C and has heat transfer to another environment at 47 ° C? COP ref (b) How much work must be done for a heat transfer of 4186 kJ from the cold environment? W = kj (c) What is the cost of doing this if the work costs 10.0 cents per 3.6 × 106 J (a kilowatt-hour)? Cost in cents = ✓ (d) How many kJ of heat transfer, Qh occurs into the warm environment? Qh= kj Think about what type of refrigerator might operate between these temperatures. Hint: Use the appropriate formula for a refrigerator which is different from a heat pump.arrow_forwardplease answer the following As a gasoline engine is running, an amount of gasoline containing 12,000 J of chemical potential energy is burned in 1 s. During that second, the engine does 4,000 J of work. What is the engine's efficiency (in percent)? The burning gasoline has a temperature of about 4,300°F (2,600 K). The waste heat from the engine flows into air at about 88°F (304 K). What is the Carnot efficiency (in percent) of a heat engine operating between these two temperatures?arrow_forwardMany decisions are made on the basis of the payback period: the time it will take through savings to equal the capital cost of an investment. Acceptable payback times depend upon the business or philosophy one has. (For some industries, a payback period is as small as two years.) Suppose you wish to install the extra insulation in Exercise. If energy cost $1.00 per million joules and the insulation was $4.00 per square meter, then calculate the simple payback time. Take the average ΔT for the 120 day heating season to be 15.0ºC.arrow_forward
- As a gasoline engine is running, an amount of gasoline containing 15,200 J of chemical potential energy is burned in 1 s. During that second, the engine does 3,800 J of work. (a) What is the engine's efficiency (in percent)? (b) The burning gasoline has a temperature of about 5,000°F (3,000 K). The waste heat from the engine flows into air at about 86°F (303 K). What is the Carnot efficiency (in percent) of a heat engine operating between these two temperatures?arrow_forwardAn engineer on Mars operates a motor that loses 45 kilojoules [kJ] of energy as heat in 20 minutes [min] and has an input power rating of 0.29 horsepower [hp]. Determine the efficiency of the motor expressed as a percentage. Click the icon to view the table of common derived units in the SI system. Click the icon to view the conversion table. Click the icon to view SI prefixes (numbers greater than one.) The thermal conductivity is %. (Round your answer to one decimal place.)arrow_forwardWould you be willing to financially back an inventor who is marketing a device that she claims has 25 kJ of heat transfer at 600 K, has heat transfer to the environment at 300 K, and does 12 kJ of work? Explain your answer.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
University Physics (14th Edition)
Physics
ISBN:9780133969290
Author:Hugh D. Young, Roger A. Freedman
Publisher:PEARSON
Introduction To Quantum Mechanics
Physics
ISBN:9781107189638
Author:Griffiths, David J., Schroeter, Darrell F.
Publisher:Cambridge University Press
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:9780321820464
Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:Addison-Wesley
College Physics: A Strategic Approach (4th Editio...
Physics
ISBN:9780134609034
Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:PEARSON