PHYSICS FOR SCIEN & ENGNR W/MOD MAST
4th Edition
ISBN: 9780134112039
Author: GIANCOLI
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 20, Problem 75GP
A cooling unit for a new freezer has an inner surface area of 6.0 m2, and is bounded by walls 12 cm thick with a thermal
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
The energy entering an electric heater by electrical transmission can be converted to internal energy with an efficiency of 100%. By what factor does the cost of heating your home change when you replace your electric heating system with an electric heat pump that has a COP of 3.50? Assume that the motor running the heat pump is 100% efficient.
A Carnot air conditioner takes energy from the thermal energy of a room at 70 F and transfers it as heat to the outdoors, which is at 96 F.For each joule of electric energy required to operate the air conditioner, how many joules are removed from the room?
I often make tea in my microwave oven. I know that it takes two minutes to bring the temperature of a cup of water from room temperature to just about boiling: ready for the teabag. I looked up the characteristics of a microwave oven. Typically their power rating is about 1000 W, but I know that this is the power consumed from the power company, not the power delivered to the water. I looked up the efficiency of microwave ovens, and found that it is about 64%, meaning that a typical oven delivers 640 W to the water. I also looked up the frequency of the microwaves that an oven uses, and found thatf= 2,450 MHz.
(a) How much energy is delivered to the water in the making of a cup of tea?
(b) What is the wavelength of the microwave?
(c) What is the energy of one microwave photon?
(d) How many microwave photons are absorbed by the water in making a cup of tea?
Chapter 20 Solutions
PHYSICS FOR SCIEN & ENGNR W/MOD MAST
Ch. 20.2 - An adiabatic process is defined as one in which no...Ch. 20.3 - A motor is running with an intake temperature TH =...Ch. 20.6 - A 1.00.kg piece of ice at 0C melts very slowly to...Ch. 20.9 - Prob. 1EECh. 20 - Prob. 1QCh. 20 - Can you warm a kitchen in winter by leaving the...Ch. 20 - Would a definition of heat engine efficiency as e...Ch. 20 - What plays the role of high-temperature and...Ch. 20 - Which will give the greater improvement in the...Ch. 20 - The oceans contain a tremendous amount of thermal...
Ch. 20 - Discuss the factors that keep real engines from...Ch. 20 - Prob. 8QCh. 20 - Describe a process in nature that is nearly...Ch. 20 - (a) Describe how heat could be added to a system...Ch. 20 - Suppose a gas expands to twice its original volume...Ch. 20 - Give three examples, other than those mentioned in...Ch. 20 - Which do you think has the greater entropy, 1 kg...Ch. 20 - (a) What happens if you remove the lid of a bottle...Ch. 20 - Prob. 15QCh. 20 - Prob. 16QCh. 20 - Prob. 17QCh. 20 - The first law of thermodynamics is sometimes...Ch. 20 - Powdered milk is very slowly (quasistatically)...Ch. 20 - Two identical systems are taken from state a to...Ch. 20 - It can he said that the total change in entropy...Ch. 20 - Use arguments, other than the principle of entropy...Ch. 20 - (I) A heat engine exhausts 7800 J of heat while...Ch. 20 - (I) A certain power plant puts out 580 MW of...Ch. 20 - (II) A typical compact car experiences a total...Ch. 20 - (II) A four-cylinder gasoline engine has an...Ch. 20 - (II) The burning of gasoline in a car releases...Ch. 20 - (II) Figure 2017 is a PV diagram for a reversible...Ch. 20 - (III) The operation of a diesel engine can be...Ch. 20 - (I) What is the maximum efficiency of a heat...Ch. 20 - (I) It is not necessary that a heat engines hot...Ch. 20 - (II) A heal engine exhausts its heat at 340C and...Ch. 20 - (II) (a) Show that the work done by a Carnot...Ch. 20 - (II) A Carnot engines operating temperatures are...Ch. 20 - (II) A nuclear power plant operates at 65% of its...Ch. 20 - (II) A Carnot engine performs work at the rate of...Ch. 20 - (II) Assume that a 65 kg hiker needs 4.0 103 kcal...Ch. 20 - (II) A particular car does work at the rate of...Ch. 20 - (II) A heat engine utilizes a heat source at 580C...Ch. 20 - (II) The working substance of a certain Carnot...Ch. 20 - (III) A Carnot cycle, shown in Fig. 20-7, has the...Ch. 20 - (III) One mole of monatomic gas undergoes a Carnot...Ch. 20 - (III) In an engine that approximates the Otto...Ch. 20 - (I) If an ideal refrigerator keeps its contents at...Ch. 20 - (I) The low temperature of a freezer cooling coil...Ch. 20 - (II) An ideal (Carnot) engine has an efficiency of...Ch. 20 - (II) An ideal heal pump is used to maintain the...Ch. 20 - (II) A restaurant refrigerator has a coefficient...Ch. 20 - (II) A heat pump is used to keep a house warm at...Ch. 20 - (II) (a) Given that the coefficient of performance...Ch. 20 - (II) A Carnot refrigerator (reverse of a Carnot...Ch. 20 - (II) A central heat pump updating as an air...Ch. 20 - (II) What volume of water at 0C can a freezer make...Ch. 20 - (I) What is the change in entropy of 250g of steam...Ch. 20 - (I) A 7.5-kg box having an initial speed of 4.0m/s...Ch. 20 - (I) What is the change in entropy of 1.00 m3 of...Ch. 20 - (II) If 1.00m3 of water at 0C is frozen and cooled...Ch. 20 - (II) If 0.45kg f water at 100C is changed by a...Ch. 20 - (II) An aluminum rod conducts 9.50 cal/s from a...Ch. 20 - (II) A 2.8-kg piece of aluminum at 43.0C is placed...Ch. 20 - (II) An ideal gas expands isothermally (T = 410 K)...Ch. 20 - (II) When 2.0 kg of water at 12.0C is mixed with...Ch. 20 - (II) (a) An ice cube of mass m at 0C is placed in...Ch. 20 - (II) The temperature of 2.0mol of an ideal...Ch. 20 - (II) Calculate the change in entropy of 1.00kg of...Ch. 20 - (II) An ideal gas of n moles undergoes the...Ch. 20 - (II) Two samples of an ideal gas are initially at...Ch. 20 - (II) A 150-g insulated aluminum cup at 15C is...Ch. 20 - (II) (a) Why would you expect the total entropy...Ch. 20 - (II) 1.00 mole of nitrogen (N2) gas and 1.00 mole...Ch. 20 - (II) Thermodynamic processes are sometimes...Ch. 20 - (III) The specific heat per mole of potassium at...Ch. 20 - (III) Consider an ideal gas of n moles with molar...Ch. 20 - (III) A general theorem states that the amount of...Ch. 20 - (III) Determine the work available in a 3.5-kg...Ch. 20 - (I) Use Eq. 2014 to determine the entropy of each...Ch. 20 - (II) Suppose that you repeatedly shake six coins...Ch. 20 - (II) Calculate the relative probabilities, when...Ch. 20 - (II) (a) Suppose you have four coins, all with...Ch. 20 - Prob. 58PCh. 20 - (II) Energy may be stored for use during peak...Ch. 20 - (II) Solar cells (Fig. 20-22) can produce about...Ch. 20 - Prob. 61PCh. 20 - It has been suggested that a heat engine could be...Ch. 20 - A heat engine takes a diatomic gas around the...Ch. 20 - A 126.5-g insulated aluminum cup at 18.00C is...Ch. 20 - (a) At a steam power plant, steam engines work in...Ch. 20 - (II) Refrigeration units can be rated in tons. A...Ch. 20 - Prob. 67GPCh. 20 - (a) What is the coefficient of performance of an...Ch. 20 - The operation of a certain heat engine takes an...Ch. 20 - A car engine whose output power is 155 hp operates...Ch. 20 - Suppose a power plant delivers energy at 850 MW...Ch. 20 - 1.00 mole of an ideal monatomic gas at STP first...Ch. 20 - Two 1100-kg cars are traveling 75 km/h in opposite...Ch. 20 - Metabolizing 1.0 kg of fat results in about 3.7 ...Ch. 20 - A cooling unit for a new freezer has an inner...Ch. 20 - Prob. 76GPCh. 20 - The Stirling cycle shown in Fig 20-27, is useful...Ch. 20 - A gas turbine operates under the Brayton cycle,...Ch. 20 - Thermodynamic processes can be represented not...Ch. 20 - An aluminum can, with negligible heat capacity, is...Ch. 20 - Prob. 81GPCh. 20 - A bowl contains a large number of red, orange, and...
Additional Science Textbook Solutions
Find more solutions based on key concepts
27. Eric has a mass of 60 kg. He is standing on a scale in an elevator that is accelerating downward at 1. 7 m/...
College Physics: A Strategic Approach (4th Edition)
The Rankine temperature scale (abbreviatedR) uses the same size degrees as Fahrenheit, but measured up from abs...
An Introduction to Thermal Physics
The number of callers required to produce intensity level of 120 dB .
Physics (5th Edition)
22. A student has 65-cm-long arms. What is the minimum angular velocity (in rpm) for swinging a bucket of water...
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
Using the definitions in Eqs. 1.1 and 1.4, and appropriate diagrams, show that the dot product and cross produc...
Introduction to Electrodynamics
A filter is a circuit designed to pass AC signals in some frequency range and to attenuate others. Common filte...
Essential University Physics: Volume 2 (3rd 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
- A water treatment plant has three flocculation compartments that water flows though sequentially (in series). The water is gently mixed in each compartment with rotating paddles, and the power input decreases as water moves through each compartment: Compartment #1: 186 W; Compartment #2: 30.0 W; Compartment #3: 7.50 W. Each compartment is 4.17 m deep, 3.75 m wide, and 4.17 m long. The water temperature is 15 °C the flow rate is 16,000 m3/day. Calculate the velocity gradient for each compartment.arrow_forwardA machinist polishes a 0.50-kg copper fitting with a piece of emery cloth for 2.0 min. He moves the cloth across the fitting at a constant speed of 1.0 m/s by applying a force of 20 N, tangent to the surface of the fitting. (a) What is the total work done on the fitting by the machinist? (b) What is the increase in the internal energy of the fitting? Assume that the change in the internal energy of the cloth is negligible and that no heat is exchanged between thefitting and its environment. (c) What is the increase in the temperature of the fitting?arrow_forwardA typical coal-fired power plant burns 340 metric tons of coal every hour to generate 2.5 × 106 MJ of energy. One metric ton has a mass of 1000 kg and a metric ton of coal has a volume of 1.5 m^3. The heat of combustion is 28 MJ/kg. What is the power plant’s efficiency?arrow_forward
- A kettle delivers 2.80 kW of power to 1.45 kg of water. The water is initially at a temperature of 23.0 °C and the kettle is 74% efficient at heating the water. Assuming the entire mass of water must be heated to the boiling point before any begins to vapourize, how long must the kettle be on in order for 0.350 kg of water to be turned to water vapour?arrow_forwardThe surface waters of tropical oceans are at a temperature of 27°C while water at a depth of 1200 m is at 3°C. It has been suggested these warm and cold waters could be the energy reservoirs for a heat engine, allowing us to do work or generate electricity from the thermal energy of the ocean. What is the maximum efficiency possible of such a heat engine?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. 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_forward
- The power output of a car engine running at 2300 rpmrpm is 300 kW . (a) How much work is done per cycle if the engine's thermal efficiency is 40.0 %?Give your answer in kJ. Win =7.83kJ (b)How much heat is exhausted per cycle if the engine's thermal efficiency is 40.0 %?Give your answer in kJ.arrow_forwardb) Energy may be stored for use during peak demand by pumping water to a high reservoir when needed. Suppose water is pumped to a lake 135 m above the turbines and at a rate of 1.35 x 10 kgs" for 10 hrs at night. ) How much energy (kWh) is needed to do this each night. i) If all this energy is released during a-14 h day, at 75% efficiency, what is the average power output? e) State three forms of environmental polution and how they can be prevented.arrow_forwardIceland has both high geothermal activity, with high temperatures near the surface, and abundant cold surface water. Iceland has many power plants that take advantage of the proximity of these natural hot and cold reservoirs. One plant uses an underground source at 122°C as the hot reservoir and a nearby lake at 5°C as the cold reservoir. The plant draws 16 MW from the hot reservoir to produce 1.8 MW of electricity. How does the actual efficiency of the plant compare to the theoretical maximum efficiency?arrow_forward
- A heat engine has a solar collector receiving 600 Btu/h per square foot, inside which a transfer medium is heated to 800 R. The collected energy powers a heat engine that rejects heat at 100 F. If the heat engine should deliver 8500 Btu/h, what is the minimum size (area) of the solar collector?arrow_forwardThe Kingda Ka roller coaster at Six Flags Great Adventure and Safari in New Jersey currently holds the world record for maximum height (139 m). A hydraulic motor accelerates the roller coaster cars to 128 mi/h before they start climbing the 139-m hill. If the cars are traveling at about 10 mi/h as they go over the top, what fraction of the cars’ original kinetic energy must have gone to some form of internal energy in the cars, track, and/or the air?arrow_forwardAn underground salt cavern has approximate dimensions of 100m x 500m x 3m. The underground salt cavern is allowed to discharge through a turbine, producing electricity. The pressure in the cavern decreases from 120 kPa to 110 kPa in 90 minutes. What was its average power output? (assume 100% efficiency) (Note: atmospheric pressure is approximately 101.3 kPa)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
Thermodynamics: Crash Course Physics #23; Author: Crash Course;https://www.youtube.com/watch?v=4i1MUWJoI0U;License: Standard YouTube License, CC-BY