University Physics (14th Edition)
14th Edition
ISBN: 9780133969290
Author: Hugh D. Young, Roger A. Freedman
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 17, Problem 17.28E
On-Demand Water Heaters. Conventional hot-water heaters consist of a tank of water maintained at a fixed temperature. The hot water is to be used when needed. The drawbacks are that energy is wasted because the tank loses heat when it is not in use and that you can run out of hot water if you use too much. Some utility companies are encouraging the use of on-demand water heaters (also known as flash heaters), which consist of heating units to heat the water as you use it. No water tank is involved, so no heat is wasted. A typical household shower flow rate is 2.5 gal/min (9.46 L/min) with the tap water being heated from 50°F (10°C) to 120°F (49°C) by the on-demand heater. What rate of heat input (either electrical or from gas) is required to operate such a unit, assuming that all the heat goes into the water?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A Carnot air conditioner takes energy from the thermal energy of a room at 59°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?
Number
Units
Use correct number of significant digits; the tolerance is +/-2%
250 students sit in an auditorium listening to a physics lecture. Because they are thinking hard, each is using 125 W of metabolic power, slightly more than they would use at rest. An air conditioner with a COP of 5.0 is being used to keep the room at a constant temperature. What minimum electric powermust be used to operate the air conditioner?
The Bodø NATO base in northern Norway uses a heat pump to extract heat from ocean water. 7.0°C ocean water is continuously drawn into the system, heat is extracted, and the water is returned to the ocean at 3.0°C. When the system is working at full capacity, 2000 kW of heat is delivered to the building at the cost of 600 kW of electric energy.a. How much energy is removed from the water (the cold reservoir) each second?b. How much water moves through the system each second?
Chapter 17 Solutions
University Physics (14th Edition)
Ch. 17 - Explain why it would not make sense to use a...Ch. 17 - If you heat the air inside a rigid, scaled...Ch. 17 - Many automobile engines have cast-iron cylinders...Ch. 17 - Why do frozen water pipes burst? Would a mercury...Ch. 17 - Two bodies made of the same material have the same...Ch. 17 - Why is it sometimes possible to loosen caps on...Ch. 17 - The inside of an oven is at a temperature of 200C...Ch. 17 - A newspaper article about the weather states that...Ch. 17 - A student asserts that a suitable unit for...Ch. 17 - Prob. Q17.10DQ
Ch. 17 - The units of specific heat c are J/kg K, but the...Ch. 17 - Why is a hot, humid day in the tropics generally...Ch. 17 - A piece of aluminum foil used to wrap a potato for...Ch. 17 - Desert travelers sometimes keep water in a canvas...Ch. 17 - When you first step out of the shower, you feel...Ch. 17 - The climate of regions adjacent to large bodies of...Ch. 17 - When water is placed in ice-cube trays in a...Ch. 17 - Before giving you an injection, a physician swabs...Ch. 17 - A cold block of metal feels colder than a block of...Ch. 17 - A person pours a cup of hot coffee, intending to...Ch. 17 - When a freshly baked apple pie has just been...Ch. 17 - Old-time kitchen lore suggests that things cook...Ch. 17 - In coastal regions in the winter, the temperature...Ch. 17 - It is well known that a potato bakes faster if a...Ch. 17 - Glider pilots in the Midwest know that thermal...Ch. 17 - Some folks claim that ice cubes freeze faster if...Ch. 17 - Were lucky that the earth isnt in thermal...Ch. 17 - Prob. Q17.28DQCh. 17 - Convert the following Celsius temperatures to...Ch. 17 - BIO Temperatures in Biomedicine. (a) Normal body...Ch. 17 - Prob. 17.3ECh. 17 - (a) Calculate the one temperature at which...Ch. 17 - You put a bottle of soft drink in a refrigerator...Ch. 17 - Prob. 17.6ECh. 17 - The pressure of a gas at the triple point of water...Ch. 17 - Prob. 17.8ECh. 17 - Prob. 17.9ECh. 17 - Prob. 17.10ECh. 17 - The Humber Bridge in England has the worlds...Ch. 17 - One of the tallest buildings in the world is the...Ch. 17 - A U.S. penny has a diameter of 1.9000 cm at 20.0C....Ch. 17 - Ensuring a Tight Fit. Aluminum rivets used in...Ch. 17 - A copper cylinder is initially at 20.0C. At what...Ch. 17 - A geodesic dome constructed with an aluminum...Ch. 17 - A glass flask whose volume is 1000.00 cm3 at 0.0C...Ch. 17 - A steel tank is completely filled with 1.90 m3 of...Ch. 17 - A machinist bores a hole of diameter 1.35 cm in a...Ch. 17 - As a new mechanical engineer for Engines Inc., you...Ch. 17 - Steel train rails are laid in 12.0-m-long segments...Ch. 17 - A brass rod is 185 cm long and 1.60 cm in...Ch. 17 - An aluminum tea kettle with mass 1.10 kg and...Ch. 17 - In an effort to stay awake for an all-night study...Ch. 17 - Prob. 17.25ECh. 17 - BIO Heat Loss During Breathing. In very cold...Ch. 17 - You are given a sample of metal and asked to...Ch. 17 - On-Demand Water Heaters. Conventional hot-water...Ch. 17 - Prob. 17.29ECh. 17 - Prob. 17.30ECh. 17 - CP A nail driven into a board increases in...Ch. 17 - A technician measures the specific heat of an...Ch. 17 - CP A 15.0-g bullet traveling horizontally at 865...Ch. 17 - You have 750 g of water at 10.0C in a large...Ch. 17 - Prob. 17.35ECh. 17 - BIO Treatment for a Stroke. One suggested...Ch. 17 - A blacksmith cools a 1.20-kg chunk of iron,...Ch. 17 - A copper calorimeter can with mass 0.100 kg...Ch. 17 - A copper pot with a mass of 0.500 kg contains...Ch. 17 - In a container of negligible mass, 0.200 kg of ice...Ch. 17 - Prob. 17.41ECh. 17 - BIO Before going in for his annual physical, a...Ch. 17 - Prob. 17.43ECh. 17 - Prob. 17.44ECh. 17 - How much heat is required to convert 18.0 g of ice...Ch. 17 - An open container holds 0.550 kg of ice at 15.0C....Ch. 17 - CP What must the initial speed of a lead bullet be...Ch. 17 - BIO Steam Burns Versus Water Burns. What is the...Ch. 17 - BIO The Ship of the Desert. Camels require very...Ch. 17 - BIO Evaporation of sweat is an important mechanism...Ch. 17 - CP An asteroid with a diameter of 10 km and a mass...Ch. 17 - A laboratory technician drops a 0.0850-kg sample...Ch. 17 - An insulated beaker with negligible mass contains...Ch. 17 - A 4.00-kg silver ingot is taken from a furnace,...Ch. 17 - A vessel whose walls are thermally insulated...Ch. 17 - Two rods, one made of brass and the other made of...Ch. 17 - Suppose that the rod in Fig. 17.24a is made of...Ch. 17 - One end of an insulated metal rod is maintained at...Ch. 17 - A carpenter builds an exterior house wall with a...Ch. 17 - An electric kitchen range has a total wall area of...Ch. 17 - BIO Conduction Through the Skin. The blood plays...Ch. 17 - A long rod, insulated to prevent heat loss along...Ch. 17 - A pot with a steel bottom 8.50 mm thick rests on a...Ch. 17 - You are asked to design a cylindrical steel rod...Ch. 17 - A picture window has dimensions of 1.40 m 2.50 m...Ch. 17 - Prob. 17.66ECh. 17 - A spherical pot contains 0.75 L of hot coffee...Ch. 17 - The emissivity of tungsten is 0.350. A tungsten...Ch. 17 - Size of a Light-Bulb Filament. The operating...Ch. 17 - The Sizes of Stars. The hot glowing surfaces of...Ch. 17 - CP A Foucault pendulum consists of a brass sphere...Ch. 17 - Suppose that a steel hoop could be constructed to...Ch. 17 - You propose a new temperature scale with...Ch. 17 - CP CALC A 250-kg weight is hanging from the...Ch. 17 - You are making pesto for your pasta and have a...Ch. 17 - A surveyors 30.0-m steel tape is correct at 20.0C....Ch. 17 - A metal rod that is 30.0 cm long expands by 0.0650...Ch. 17 - On a cool (4.0C) Saturday morning, a pilot fills...Ch. 17 - (a) Equation (17.12) gives the stress required to...Ch. 17 - CP A metal wire, with density and Youngs modulus...Ch. 17 - A steel ring with a 2.5000-in. inside diameter at...Ch. 17 - BIO Doughnuts: Breakfast of Champions! Atypical...Ch. 17 - BIO Shivering. Shivering is your bodys way of...Ch. 17 - You cool a 100.0-g slug of red-hot iron...Ch. 17 - CALC Debyes T3 Law. At very low temperatures the...Ch. 17 - CP A person of mass 70.0 kg is sitting in the...Ch. 17 - Hot Air in a Physics Lecture. (a) A typical...Ch. 17 - CALC The molar heat capacity of a certain...Ch. 17 - Prob. 17.89PCh. 17 - BIO Overheating. (a) By how much would the body...Ch. 17 - BIO A Thermodynamic Process in an Insect. The...Ch. 17 - Hot Water Versus Steam Heating. In a household...Ch. 17 - You have 1.50 kg of water at 28.0C in an insulated...Ch. 17 - A thirsty nurse cools a 2.00-L bottle of a soft...Ch. 17 - Prob. 17.95PCh. 17 - A Styrofoam bucket of negligible mass contains...Ch. 17 - In a container of negligible mass, 0.0400 kg of...Ch. 17 - Prob. 17.98PCh. 17 - Effect of a Window in a Door. A carpenter builds a...Ch. 17 - One experimental method of measuring an insulating...Ch. 17 - Compute the ratio of the rate of heat loss through...Ch. 17 - Rods of copper, brass, and steeleach with...Ch. 17 - A brass rod 12.0 cm long, a copper rod 18.0 cm...Ch. 17 - BIO Basal Metabolic Rate. The basal metabolic rate...Ch. 17 - Prob. 17.105PCh. 17 - Prob. 17.106PCh. 17 - A Thermos for Liquid Helium. A physicist uses a...Ch. 17 - A metal sphere with radius 3.20 cm is suspended in...Ch. 17 - Prob. 17.109PCh. 17 - The icecaps of Greenland and Antarctica contain...Ch. 17 - DATA As a physicist, yon put heat into a 500.0-g...Ch. 17 - DATA At a chemical plant where you are an...Ch. 17 - DATA During your mechanical engineering...Ch. 17 - Prob. 17.114CPCh. 17 - A hollow cylinder has length L, inner radius a,...Ch. 17 - You place 35 g of this cryoprotectant at 22C in...Ch. 17 - Careful measurements show that the specific heat...Ch. 17 - In another experiment, you place a layer of this...Ch. 17 - To measure the specific heat in the liquid phase...
Additional Science Textbook Solutions
Find more solutions based on key concepts
Whats the electric field strength in a region where the flux through a 1.0 cm 1.0 cm flat surface is 65 N m2/C...
Essential University Physics (3rd Edition)
This problem returns to the tightrope walker studied in Example 4.6, who created a tension of 3.94103 N in a wi...
College Physics
Different materials, A, B, C, and D, rest on a table. a From greatest to least, rank them by how much they resi...
Conceptual Integrated Science
Use unit vectors to express a displacement of 120 km at 29 counterclockwise from the x-axis.
Essential University Physics: Volume 1 (3rd Edition)
Which value, apparent magnitude, or absolute magnitude, do you think:
tells us how bright an object will appear...
Lecture- Tutorials for Introductory Astronomy
16.29 The longest pipe found in most medium-size pipe organs is 4.88 m (16 ft) long. What is the frequency of t...
University Physics with Modern Physics (14th 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 power plant has been proposed that would make use of the temperature gradient in the ocean. The system is to operate between 20.0C (surface water temperature) and 5.00C (water temperature at a depth of about 1 km). (a) What is the maximum efficiency of such a system? (b) If the useful power output of the plant is 75.0 MW, how much energy is absorbed per hour? (c) In view of your answer to part (a), do you think such a system is worthwhile (considering that there is no charge for fuel)?arrow_forwardA refrigerator’s freezer compartment is set at –10°C; the kitchen is 24°C. What is the theoretical minimum amount of electric energy necessary to pump 1.0 J of energy out of the freezer compartment?A. 0.89 J B. 0.87 J C. 0.13 J D. 0.11 Jarrow_forwardA 32% efficient electric power plant produces 900 MJ of electric energy per second and discharges waste heat into 20°C ocean water. Suppose the waste heat could be used to heat homes during the winter instead of being discharged into the ocean. A typical American house requires an average 20 kW for heating. How many homes could be heated with the waste heat of this one power plant?arrow_forward
- If you mix food in a blender, the electric motor does work on the system, which consists of the food inside the container. This work can noticeably warm up the food. Suppose the blender motor runs at a power of 250 W for 40 s. During this time, 2000 J of heat flow from the now-warmer food to its cooler surroundings. By how much does the thermal energy of the food increase?arrow_forwardAn automobile engine converts heat into work via a cycle. The cycle must finish exactly where it started, so the energy at the start of the cycle must be exactly the same as the energy at the end of the cycle. If the engine absorbs 226 J of heat per cycle, how much work can it do per cycle?arrow_forwardIf you mix food in a blender, the electric motor does work on the system, which consists of the food inside the container. This work can noticeably warm up the food. Suppose the blender motor runs at a power of 250 W for 40 s. During this time, 2000 J of heat flow from the now-warmer food to its cooler surroundings. Match the answers with questions. (Hint: Example 11.12) v W- work done on the system (food) A. 2000 J v Q- Heat into or out of the system (food) B. 8000 J v AEth - Change in thermal energy of the system (food) C. OJ D. -10,000 J E. -8000 J F. -2000 J G. 10,000 Jarrow_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_forwardm = 0.593 kg of methanol in atmospheric pressure is heated with an electric heater from T₁ = 30.2 °C to its boiling point. After the heating my methanol is vaporized. Heating and vaporizing takes t = 450.41 s with n=0.59 heater's efficiency. What is the volume of methanol? V = What is the energy required for heating? E₁ = 1 kJ m³ Your last answer was interpreted as follows: 1 What is the energy required for vaporizing? Ev = 1 kJ Your last answer was interpreted as follows: 1 What is the power of the heater? P = 1 с Your last answer was interpreted as follows: 1 Your last answer was interpreted as follows: 1 What is the electr. energy needed for heating and vaporizing? Eε = 1 kJ Your last answer was interpreted as follows: 1 h Do not leave any fields blank. If you don't know the answer, insert 1 for example. Insert the answer with 3 significant digits without rounding the answer. Constant P Tb Value Unit 2.53 1165 786.3 64.7 °C umges Quantity heat capacity kg K kJ kW kg kg LAN Symbol h…arrow_forwardAn insulated 40-ft3 rigid tank contains air at 50 psia and 120°F. A valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. The air temperature during this process is maintained constant by an electric resistance heater placed in the tank. Determine the electrical work done during this process.arrow_forward
- A steam engine has a boiler that operates at 500 K. The energy from the burning fuel changes water to steam, and this steam then drives a piston. The cold reservoir’s temperature is that of the outside air, approximately 300 K. What is the maximum thermal efficiency of this steam engine?arrow_forwardAn aircraft engine takes in 8900 JJ of heat and discards 6700 JJ each cycle. Part A. What is the mechanical work output of the engine during one cycle? Part B. What is the thermal efficiency of the engine? Express your answer as a percentage.arrow_forwardDuring each cycle of operation, a refrigerator absorbs 230 J of heat from the freezer and expels 356 J of heat to the room. How much work input is required in each cycle? 310 J 460 J O 126 J 712 J O 586 Jarrow_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
College PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
College PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
Physics for Scientists and EngineersPhysicsISBN:9781337553278Author: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
College Physics
Physics
ISBN:9781285737027
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Physics for Scientists and Engineers with Modern ...
Physics
ISBN:9781337553292
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
College Physics
Physics
ISBN:9781938168000
Author:Paul Peter Urone, Roger Hinrichs
Publisher:OpenStax College
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Heat Transfer: Crash Course Engineering #14; Author: CrashCourse;https://www.youtube.com/watch?v=YK7G6l_K6sA;License: Standard YouTube License, CC-BY