College Physics
OER 2016 Edition
ISBN: 9781947172173
Author: OpenStax
Publisher: OpenStax College
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 15, Problem 42PE
(a) What is the best coefficient of performance for a refrigerator that cools an environment at
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
(a) What is the best coefficient of performance for a refrigerator that cools an environment at −30.0ºC and has heat transfer to another environment at 45.0ºC ? (b) How much work in joules must be done for a heat transfer of 4186kJ from the cold environment? (c) What is the cost of doing this if the work costs 10.0 cents per 3.60×106 J (a kilowatthour)?(d) How many kJ of heat transfer occurs into the warm environment?(e) Discuss what type of refrigerator might operate between these temperatures.
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 output
(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 49 ° C?
COP,
= 3.18
ref
(b) How much work must be done for a heat transfer of 4186 kJ from the cold environment?
W = 1316.4
kJ
(c) What is the cost of doing this if the work costs 10.0 cents per 3.6x10° J (a kilowatt-hour)?
Cost in cents = 3.66
(d) How many kJ of heat transfer, Q, occurs into the warm environment?
Qn
= 1314.5
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 - Prob. 20CQCh. 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 - Prob. 1TPCh. 15 - Prob. 2TPCh. 15 - Prob. 3TPCh. 15 - Prob. 4TPCh. 15 - Prob. 5TPCh. 15 - Prob. 6TPCh. 15 - Prob. 7TPCh. 15 - Prob. 8TPCh. 15 - Prob. 9TPCh. 15 - Prob. 10TPCh. 15 - Prob. 11TPCh. 15 - Prob. 12TPCh. 15 - Prob. 13TPCh. 15 - Prob. 14TPCh. 15 - Prob. 15TPCh. 15 - Prob. 16TP
Additional Science Textbook Solutions
Find more solutions based on key concepts
3. CAUTION Why is genetic drift aptly named?
a. It causes allele frequencies to drift up or down randomly.
b. I...
Biological Science (6th Edition)
For the generic equilibrium HA(aq) ⇌ H + (aq) + A- (aq), which of these statements is true?
The equilibrium con...
Chemistry: The Central Science (14th Edition)
Match the following cell types with their correct definition. _________Macrophage _________NK cell _________Eos...
Human Anatomy & Physiology (2nd Edition)
2. The three ropes in FIGURE EX6.2 are tied to a small, very light ring. Two of the ropes are anchored to wa...
Physics for Scientists and Engineers: A Strategic Approach, Vol. 1 (Chs 1-21) (4th Edition)
Consider two hypothetical recessive autosomal genes a and b, where a heterozygote is testcrossed to a double-ho...
Concepts of Genetics (12th Edition)
If someone at the other end of a room smokes a cigarette, you may breathe in some smoke. The movement of smoke ...
Campbell Essential Biology with Physiology (5th Edition)
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
- 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.arrow_forward(a) How much heat transfer occurs to the environment by an electrical power station that uses 1.25×1014 J of heat transfer into the engine with an efficiency of 42.0%? (b) What is the ratio of heat transfer to the environment to work output? (c) How much work is done?arrow_forwardA 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.arrow_forward
- Answer the following ASAP: A gasoline engine has a power output of 200 kW. Its thermal efficiency is 35.0%. (a) How much heat must be supplied to the engine per second? (b) How much heat is discarded by the engine per second?arrow_forwardA large electrical power station generates 1050 MW of electricity with an efficiency of 37.0%. (a) Calculate the heat transfer (in J) to the power station, Q, in one day. (b) How much heat transfer Q. (in J) occurs to the environment in one day? (c) If the heat transfer in the cooling towers is from 35.0°C water into the local air mass, which increases in temperature from 18.0°C to 20.0°C, what is the total increase in entropy (in J/K) due to this heat transfer? J/K (d) How much energy (in J) becomes unavailable to do work because of this increase in entropy, assuming an 18.0°C lowest temperature? (Part of Q. could be utilized to operate heat engines or for simple space heating, but it rarely is.) to Additional Materials O Reading CS Scanned with CamScannerarrow_forward5. (a) How much heat transfer occurs to the environment by an electrical power station that uses1.25 × 10^14 J of heat transfer into the engine with an efficiency of 42.0%? (b) What is the ratioof heat transfer to the environment to work output? (c) How much work is done?arrow_forward
- A heat pump is a heating system that has an efficiency of about 150 %, that is,for every joule (J) the electrical energy consumed, 1.5 J of heat is produced. Yet according to the law from energy conservation, the energy efficiency of a device should never come into over 100%, since energy cannot be created or destroyed. So there is thermal energy that is transferred from the outside to the inside of the house. Explain why this phenomenon remains possible, even under 0 °C.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_forward(a) What is the best coefficient of performance for a refrigerator that cools an environment at -28.5°C and has heat transfer to another environment at 46.5°C? 3.262 (b) How much work in joules must be done for a heat transfer of 4186 kJ from the cold environment? 1283.26 (c) What is the cost (in cents) of doing this if the work costs 15.0 cents per 3.60 x 106 J (a kilowatt-hour)? 5.35 (d) How many k) of heat transfer occurs into the warm environment? 5469.26 kJ (e) Discuss what type of refrigerator might operate between these temperatures. The inside of the refrigerator (actually freezer) is at (-28.5 °C) so this probably is a commercial meat packing freezer. The exhaust is generally vented to the outside so as to not heat the building too much.arrow_forward
- As a gasoline engine is running, an amount of gasoline containing 16,000 J of chemical potential energy is burned in 1 s. During that second, the engine does 4,000 J of work. (a) What is the engine's efficiency (in percent)? % The burning gasoline has a temperature of about 4,700°F (2,900 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? (b) %arrow_forwardAs 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_forwardThis problem compares the energy output and heat transfer to the environment by two different types of nuclear power stations—one with the normal efficiency of 34.0%, and another with an improved efficiency of 40.0%. Suppose both have the same heat transfer into the engine in one day, 2.50×1014 J . (a) How much more electrical energy is produced by the more efficient power station? (b) How much less heat transfer occurs to the environment by the moreefficient power station? (One type of more efficient nuclear power station, the gas-cooled reactor, has not been reliable enough to be economically feasible in spite of its greater efficiency.)arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
The Second Law of Thermodynamics: Heat Flow, Entropy, and Microstates; Author: Professor Dave Explains;https://www.youtube.com/watch?v=MrwW4w2nAMc;License: Standard YouTube License, CC-BY