HEAT+MASS TRANSFER:FUND.+APPL.
6th Edition
ISBN: 9780073398198
Author: CENGEL
Publisher: RENT MCG
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 1, Problem 143P
A 2-kW electric resistance heater submerged in 30-kg water is turned on and kept on for 10 min. During the process, 500 kJ of heat is lost from the water. The temperature rise of the water is
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Question 2. A household with electric resistance heating plans to switch from resistive heating
to a ground source heat pump. Annual heat consumption of the house is 30 000 kWh.
Investment cost of the heat pump is 21 000 €. Heat pumps COP is 4.0. How much are the
annual savings compared to resistive heating after the change of the heating system (in kWh)?
Average price of electricity is assumed to be 12 c/kWh. Round off your answer to one decimal
digit and enter it without the unit.
A vertical piston cylinder assembly containing water is being heated on a stove. During this
process, 100 BTU of heat is transferred to the water. In the water's expansion process (because
of the heat addition) 8000 ft- Ibf of work is done. Also, there is 20 BTU heat loss from the assembly.
What is the water's change of energy as a result of the heat addition process?
Mof 2629 k/ks ot 70
3. A classroom that normally contains 40 people is to be air-conditioned with window air-conditioning units of 5-kW cooling capacity. A person at rest may be assumed to dissipate heat at a rate of about 360 kJ/h. There are 10 light bulbs in the room, each with a rating of 100 W. The rate of heat transfer to the classroom through the walls and the windows is estimated to be 15,000 kJ/h. If the room air is to be maintained at a constant temperature of 210C, determine the number of window air-conditioning units required. draw a figure also, and explain each step by step solution.
Chapter 1 Solutions
HEAT+MASS TRANSFER:FUND.+APPL.
Ch. 1 - How does the science of heat transfer differ from...Ch. 1 - What is the driving force for (a) heat transfer,...Ch. 1 - How do rating problems in heat transfer differ...Ch. 1 - What is the difference between the analytical and...Ch. 1 - What is the importance of modeling in engineering?...Ch. 1 - When modeling an engineering process, how is the...Ch. 1 - On a hot summer day, a student turns his fan on...Ch. 1 - Consider two identical rooms, one with a...Ch. 1 - Prob. 9CPCh. 1 - Prob. 10CP
Ch. 1 - Prob. 11CPCh. 1 - An ideal gas is heated from 50C to 80C (a) at...Ch. 1 - What is heat flux? How is it related to the heat...Ch. 1 - What are the mechanisms of energy transfer to a...Ch. 1 - A logic chip used in a computer dissipates 3 W of...Ch. 1 - Consider a 150-W incandescent lamp. The filament...Ch. 1 - A 15-cm-diameter aluminum ball is to be heated...Ch. 1 - A 60-gallon water heated is initially filled with...Ch. 1 - Prob. 19PCh. 1 - Prob. 20PCh. 1 - Prob. 21PCh. 1 - Prob. 22PCh. 1 - Prob. 23PCh. 1 - Prob. 24PCh. 1 - Prob. 25PCh. 1 - Prob. 26PCh. 1 - A 5-m6-m8-m room is to be heated by an electrical...Ch. 1 - Prob. 28PCh. 1 - Air enters the duct of an air-conditioning system...Ch. 1 - Prob. 30PCh. 1 - Define thermal conductivity, and explain its...Ch. 1 - Which is a better heat conductor, diamond or...Ch. 1 - How do the thermal conductivity of gases and...Ch. 1 - Why is the thermal conductivity of superinsulation...Ch. 1 - Why do we characterize the heat conduction ability...Ch. 1 - What are the mechanisms of heat transfer? How are...Ch. 1 - Write down the expression for the physical laws...Ch. 1 - How does heat conduction differ from convection?Ch. 1 - Does any of the energy of the sun reach the earth...Ch. 1 - How does forced convection differ from natural...Ch. 1 - What is the physical mechanism of heat conduction...Ch. 1 - Consider heat transfer a windowless wall of house...Ch. 1 - Consider heat loss through two walls of house on a...Ch. 1 - Consider two houses that are identical except that...Ch. 1 - Consider two walls of a house that are identical...Ch. 1 - Define emissivity and absorptivity. What is...Ch. 1 - What is a blackbody? How do real bodies differ...Ch. 1 - A wood slab with a thickness 0.05 m is subjected...Ch. 1 - Prob. 49PCh. 1 - Prob. 50EPCh. 1 - The inner and outer surfaces of a 0.5-cm thick...Ch. 1 - Prob. 52PCh. 1 - Prob. 53PCh. 1 - The north wall of an electrically heated home is...Ch. 1 - Prob. 55PCh. 1 - Prob. 56PCh. 1 - Prob. 57PCh. 1 - A concreate wall a surface area of 20 m2 and a...Ch. 1 - Prob. 59PCh. 1 - Prob. 60PCh. 1 - Prob. 61PCh. 1 - Prob. 62EPCh. 1 - Air at 20C with a convection heat transfer...Ch. 1 - Prob. 64PCh. 1 - Prob. 65PCh. 1 - Prob. 66PCh. 1 - Prob. 67PCh. 1 - Prob. 68PCh. 1 - Prob. 69PCh. 1 - Prob. 70PCh. 1 - Prob. 71PCh. 1 - Prob. 72EPCh. 1 - Prob. 73PCh. 1 - Prob. 74PCh. 1 - Prob. 75PCh. 1 - Prob. 76PCh. 1 - Using the conversion factors between W and Btu/h,...Ch. 1 - The outer surface of a spacecraft in space has an...Ch. 1 - Consider a person whose expose surface are is 1.7...Ch. 1 - Prob. 80PCh. 1 - Two surfaces, one highly polished and the other...Ch. 1 - A spherical interplanetary probe with a diameter...Ch. 1 - Prob. 83PCh. 1 - Can all three modes of heat transfer occur...Ch. 1 - Can a medium involve (a) conduction and...Ch. 1 - The deep human body temperature of a healthy...Ch. 1 - We often turn the fan on in summer to help us...Ch. 1 - Prob. 88PCh. 1 - Prob. 89PCh. 1 - Prob. 90PCh. 1 - An electronic package with a surface area of 1 m2...Ch. 1 - Consider steady heat transfer between two large...Ch. 1 - Prob. 93PCh. 1 - Prob. 94PCh. 1 - A 2-in-diameter spherical ball whose surface is...Ch. 1 - Prob. 96PCh. 1 - Prob. 97PCh. 1 - A 3-m-internal-diameter spherical tank made of...Ch. 1 - Prob. 99PCh. 1 - Solar radiation is incident on a 5-m2 solar...Ch. 1 - Prob. 101PCh. 1 - Prob. 102PCh. 1 - Prob. 103EPCh. 1 - An AISI 304 stainless steel sheet is going through...Ch. 1 - Prob. 105PCh. 1 - Prob. 106PCh. 1 - Prob. 107PCh. 1 - Prob. 108CPCh. 1 - Prob. 109PCh. 1 - Prob. 110PCh. 1 - Prob. 111PCh. 1 - Prob. 112PCh. 1 - Prob. 113CPCh. 1 - Why is the metabolic rate of women, in general,...Ch. 1 - What is asymmetric thermal radiation How does it...Ch. 1 - How do (a) draft and (b) cold floor surfaces cause...Ch. 1 - Prob. 117CPCh. 1 - Why is it necessary to ventilate buildings? What...Ch. 1 - Consider a house in Atlanta, Georgia, that is...Ch. 1 - Prob. 120PCh. 1 - A 4m5m6m and room is to be heated by one ton (1000...Ch. 1 - Engine valves (cp=440J/kg.Kandp=7840kg/m3) are to...Ch. 1 - Prob. 123PCh. 1 - Prob. 124PCh. 1 - A 0.3 -cm-thick, 12-cm-high, and 18-cm-long...Ch. 1 - A 40-cm-long, 800-W electric resistance heating...Ch. 1 - It is well known that wind makes the cold air feel...Ch. 1 - An engine block with a surface area measured to be...Ch. 1 - Prob. 129PCh. 1 - Prob. 130PCh. 1 - Prob. 131PCh. 1 - Consider a person standing in a room maintained at...Ch. 1 - Prob. 133PCh. 1 - Prob. 134PCh. 1 - Prob. 135PCh. 1 - Prob. 136PCh. 1 - Prob. 137PCh. 1 - Prob. 138PCh. 1 - Prob. 139PCh. 1 - Prob. 140PCh. 1 - Prob. 141PCh. 1 - Prob. 142PCh. 1 - A 2-kW electric resistance heater submerged in...Ch. 1 - Prob. 144PCh. 1 - A cold bottled drink (m=2.5kg,cp=4200J/kg.K) at...Ch. 1 - Prob. 146PCh. 1 - Air enters a 12-m-long, 7-cm-diameter pipe at 50oC...Ch. 1 - Prob. 148PCh. 1 - Steady heat conduction occurs through a...Ch. 1 - Heat is lost through a brick wall (k=0.72W/m.K),...Ch. 1 - Prob. 151PCh. 1 - A 40-cm-long, 0.4-cm-diameter electric resistance...Ch. 1 - Prob. 153PCh. 1 - Prob. 154PCh. 1 - Over 90 percent of the energy dissipated by an...Ch. 1 - On a still, cleat night, the sky appears to be a...Ch. 1 - Prob. 157PCh. 1 - Prob. 158PCh. 1 - A persons head can be approximated as a...Ch. 1 - A person standing in a room loses heat to the air...Ch. 1 - Write an essay on how microwave ovens work, and...Ch. 1 - Using information form the utility bill for the...Ch. 1 - It is well know that at the same outdoor air...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- One British thermal unit will raise the temperature of _____ 1b of water _____F.arrow_forward8.12 An electric room heater has been designed in the shape of a vertical cylinder 2 m tall and 30 cm in diameter. For safety, the heater surface cannot exceed . If the room air is at , find the power rating of the heater in watts.arrow_forwardWhat is the heat transfer rate of initial temperature of 26 degree Celsius and the final temperature is 85 degree Celsius.arrow_forward
- An electric home stove with 3 burners and microwave is used in preparing a meal asfollows. Burner 1: 20 minutes Burner 2: 40 minutes Burner 3: 15 minutes . Microwave: 30minutes. If each burner is rated at 1.2 kW and the oven at 1.8 kW, and electricity costs 1000(IQ =Iraqi Dinar) per k Wh, calculate the cost of electricity used in preparing the meal?arrow_forwardThe Ocean Thermal Energy Conversion (OTEC) system in Hawali utilizes the surface water and deep water as thermal energy reservoirs Assume the ocean lemperature at the surface to be 20 "C and at some depth to be 6 C Determine the maximum possible thermal efficiency achievable by a heat engine. Express the thermal efficiency as a percentage to three significant figures. Thh = 478 % Previous Answers V Correctarrow_forwardConsider you have conducted a lab work to analysis the system performance of an air conditioning system. Given that the refrigerant is R-134a. Table below shows the data collection on the 4 main sections of the system. Given that the heat loss from the compressor to the ambient is about 12 kJ/kg, and the ambient air temperature and the refrigerated space temperature are 36 °C and 10 C, respectively. Ignore the heat transfer in all the connecting lines between the components. Low Pressure 3.6 bar High Pressure 16 bar * Accuracy of the temperature measurement is about +1 °C T1 T2 T3 T4 10°C 75°C 44 °C 5 °C (a) Sketch a T-s diagram to show the above process. (b) Calculate the coefficient of performance (COP) of the refrigeration cycle. (c) Conduct the entropy analysis for each major component, and suggest a component that should be redesigned to improve the overall system performance. [2.678, Sgen4-1= 0.007635 kJ/(Kg K), Sgenl-2= 0.066885 kJ/(Kg-K), Sgen2-3= 0.041447 kJ/(Kg K), Sgen3-4=…arrow_forward
- THERMODYNAMICS 11 kg of air is heated from 24 to 84 degrees celcius in a piston-cylinder device by passing electricity via a resistive heater within the cylinder. The pressure within the cylinder is remained constant at 300 kPa during the procedure, and a 78 kJ heat loss occurs what is the kWh value of the supplied electric energy?arrow_forwardDetermine the quantity (volume) of saline water in a steam generator. The heat energy of 1576 kJ is supplied to saline water in the steam generator to heat from 22°C to 123°C for the generation of water vapor, Take the density & specific heat of the solution as 1033 kg/m & 3.7 J/kg°K respectively. Solution: Change in Temperature (in K) 101 Mass of the saltwater (in kg) 4217.28 Quantity (Volume) of saltwater (in m) 4.082arrow_forwardAn electric motor is used to drive the shaft of a small water pump. During a performance test, the torque on the motor shaft is found to be 5.549 N.m when the motor is drawing 687.12 W of electrical power. What's the rotational speed of the shaft in rpm?arrow_forward
- What is a K system?arrow_forward. a. A group of engineering students designs an electric heater with a power rating of 15 kW. If 10 kg of ice at 200 K is placed in the heater, how many minutes will it take to change ice to steam at 400 K. Assume 100% efficient.arrow_forward3: Determine the second law efficiency of the heat engine operating between “550” ºC and “30” ºC. The heat engine has efficiency of “35” %arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license