Heat and Mass Transfer: Fundamentals and Applications
5th Edition
ISBN: 9780073398181
Author: Yunus A. Cengel Dr., Afshin J. Ghajar
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 4, Problem 10CP
Consider two identical 4-kg pieces of roast beef. The first piece is baked as a whole, while the second is baked after being cut into two equal pieces in the same oven. Will there be any difference between the cooking times of the whole and cut roasts? Why?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Question : Studies show that the major energy consumption in Fijian villages is wood which is used for cooking over open fires. Typical consumption of wood is 1 kg person–1day–1.
(a) Estimate the heat energy required to boil a 2-liter pot full of water. Assuming this to be the cooking requirement of each person, compare this with the heat content of the wood, and thus estimate the thermal efficiency of the open fire.
(b) How much timber has to be felled each year to cook for a village of 200 people?Assuming systematic replanting, what area of crop must the village therefore set aside for fuel use if it is not to make a net deforestation? Hint: refer to Table 10.4.
(c) Comment on the realism of the assumptions made, and revise your estimates accordingly.
Answer: (a) mcDT ≈ 0.6 MJ (heat losses from pot imply actual requirement is higher). h ≈ 3%. (b) 70 tonnes; 7 ha.
During hot summer weather, many people put “koozies” around their beverages to keep the drinks cold. In addition to preventing a warm hand from heating the container through conduction, what other mechanisms slow the process of warming beverages?
What four processes are involved in heat transfer?
Chapter 4 Solutions
Heat and Mass Transfer: Fundamentals and Applications
Ch. 4 - What is the physical significance of the Biot...Ch. 4 - What is lumped system analysis? When is it...Ch. 4 - In what medium is the lumped system analysis more...Ch. 4 - For which solid is the lumped system analysis more...Ch. 4 - For which kinds of bodies made of the same...Ch. 4 - Consider heat transfer between two identical hot...Ch. 4 - Consider heat transfer between two identical hot...Ch. 4 - Consider a hot baked potato on a plate. The...Ch. 4 - Consider a potato being baked in an oven that is...Ch. 4 - Consider two identical 4-kg pieces of roast beef....
Ch. 4 - Consider a sphere and a cylinder of equal volume...Ch. 4 - Obtain relations for the characteristic lengths of...Ch. 4 - Obtain a relation for the time required for a...Ch. 4 - A brick of 20310257mm in dimension is being burned...Ch. 4 - Prob. 15PCh. 4 - Prob. 16PCh. 4 - Metal plates...Ch. 4 - Prob. 18PCh. 4 - Prob. 19PCh. 4 - A 6-mm-thick stainless steel strip...Ch. 4 - After heat treatment, the 2-cm-thick metal plates...Ch. 4 - A long copper rod of diameter 2.0 cm is initially...Ch. 4 - Prob. 23PCh. 4 - Steel rods...Ch. 4 - To warm up some milk for a baby, a mother pours...Ch. 4 - A person is found dead at 5 p.m. in a room whose...Ch. 4 - Prob. 27PCh. 4 - In an experiment, the temperature of a hot gas...Ch. 4 - Prob. 29PCh. 4 - Pulverized coal particles are used in oxy-fuel...Ch. 4 - Oxy-fuel combustion power plants use pulverized...Ch. 4 - Plasma spraying is a process used for coating a...Ch. 4 - Consider a spherical shell satellite with outer...Ch. 4 - Prob. 34PCh. 4 - Prob. 35PCh. 4 - Prob. 36EPCh. 4 - Consider a sphere of diameter 5 cm, a cube of side...Ch. 4 - Prob. 38PCh. 4 - An egg is to be cooked to a certain level of...Ch. 4 - What is an infinitely long cylinder? When is it...Ch. 4 - What is the physical significance of the Fourier...Ch. 4 - Prob. 42CPCh. 4 - Prob. 43CPCh. 4 - Prob. 44CPCh. 4 - The Biot number during a heat transfer process...Ch. 4 - A body at an initial temperature of Ti, is brought...Ch. 4 - Prob. 47PCh. 4 - In a meat processing plant, 2-cm-thick steaks...Ch. 4 - Prob. 49PCh. 4 - Prob. 50PCh. 4 - Prob. 51PCh. 4 - Layers of 23-cm-thick meat slabs...Ch. 4 - Prob. 53PCh. 4 - Prob. 54PCh. 4 - Prob. 55EPCh. 4 - Prob. 56PCh. 4 - Prob. 57EPCh. 4 - Prob. 58PCh. 4 - A 30-cm-diameter, 4-m-high cylindrical column of a...Ch. 4 - Prob. 60PCh. 4 - Prob. 61PCh. 4 - Prob. 62PCh. 4 - Prob. 63PCh. 4 - Prob. 64PCh. 4 - Prob. 65PCh. 4 - Prob. 66PCh. 4 - Prob. 67PCh. 4 - Prob. 68PCh. 4 - Prob. 69PCh. 4 - For heat transfer purposes, an egg can be...Ch. 4 - Citrus fruits are very susceptible to cold...Ch. 4 - Prob. 72PCh. 4 - Prob. 73PCh. 4 - A 9-cm-diameter potato...Ch. 4 - Chickens with an average mass of 1.7 kg...Ch. 4 - Prob. 76PCh. 4 - In Betty Crocker s Cookbook, it is stated that it...Ch. 4 - Prob. 78PCh. 4 - Prob. 79PCh. 4 - Oranges of 2.5-in-diameter...Ch. 4 - Prob. 81EPCh. 4 - Under what conditions can a plane wall be treated...Ch. 4 - What is a semi-infinite medium? Give examples of...Ch. 4 - Consider a hot semi-infinite solid at an initial...Ch. 4 - Prob. 85EPCh. 4 - Prob. 86PCh. 4 - In areas where the air temperature remains below...Ch. 4 - Prob. 88PCh. 4 - A highway made of asphalt is initially at a...Ch. 4 - A thick aluminum block initially at 20C is...Ch. 4 - Prob. 91PCh. 4 - A thick wall made of refractory bricks...Ch. 4 - Prob. 93PCh. 4 - Prob. 94PCh. 4 - A thick wood slab (k=0.17W/m.K,=1.2810-7m2/s) and...Ch. 4 - Prob. 96PCh. 4 - Prob. 97PCh. 4 - Prob. 98PCh. 4 - Prob. 99PCh. 4 - Prob. 100PCh. 4 - Prob. 101PCh. 4 - A barefooted person whose feet are at 32C steps on...Ch. 4 - What is the product solution method? How is it...Ch. 4 - How is the product solution used to determine the...Ch. 4 - Prob. 105CPCh. 4 - Consider a short cylinder whose top and bottom...Ch. 4 - Prob. 107PCh. 4 - Prob. 108PCh. 4 - A hot dog can be considered to be a cylinder 5 in...Ch. 4 - Prob. 110PCh. 4 - Prob. 111PCh. 4 - A 2-cm-high cylindrical ice block...Ch. 4 - Prob. 113PCh. 4 - Prob. 114PCh. 4 - Prob. 115PCh. 4 - Prob. 116PCh. 4 - Prob. 117PCh. 4 - Prob. 118PCh. 4 - Prob. 119CPCh. 4 - How does refrigeration prevent or delay the...Ch. 4 - What are the environmental factors that affect the...Ch. 4 - What is the effect of cooking on the...Ch. 4 - Prob. 123CPCh. 4 - Prob. 124CPCh. 4 - Prob. 125CPCh. 4 - Prob. 126CPCh. 4 - How does the rate of freezing affect the...Ch. 4 - Prob. 128CPCh. 4 - Prob. 129CPCh. 4 - Prob. 130CPCh. 4 - Prob. 131CPCh. 4 - Prob. 132CPCh. 4 - Prob. 133PCh. 4 - Prob. 134PCh. 4 - Chickens with an average mass of 2.2 kg and...Ch. 4 - Prob. 136EPCh. 4 - Prob. 137PCh. 4 - Prob. 138PCh. 4 - A long roll of 2-m-wide and 0.5-cm-thick 1-Mn...Ch. 4 - Prob. 140PCh. 4 - Prob. 141PCh. 4 - Prob. 142PCh. 4 - During a picnic on a hot summer day, the only...Ch. 4 - Two metal rods are being heated in an oven with...Ch. 4 - Stainless steel ball bearings...Ch. 4 - Prob. 146PCh. 4 - Prob. 147PCh. 4 - In Betty crockers Cookbook, it is stated that it...Ch. 4 - A watermelon initially at 35C is to be cooled by...Ch. 4 - Prob. 150PCh. 4 - Prob. 151PCh. 4 - Prob. 152PCh. 4 - Prob. 153PCh. 4 - Prob. 154PCh. 4 - Prob. 155PCh. 4 - Prob. 156PCh. 4 - Prob. 157PCh. 4 - Prob. 158PCh. 4 - Prob. 159PCh. 4 - Lumped system analysis of transient heat...Ch. 4 - Prob. 161PCh. 4 - Prob. 162PCh. 4 - An 18-cm-long, 16-cm-wide, and 12-cm-high hot iron...Ch. 4 - Prob. 164PCh. 4 - Prob. 165PCh. 4 - Prob. 166PCh. 4 - Prob. 167PCh. 4 - Prob. 168PCh. 4 - A long 18-cm-diameter bar made of hardwood...Ch. 4 - Consider a 7.6-cm-long and 3-cm-diameter...Ch. 4 - Consider a 7.6-cm-diameter cylindrical lamb meat...Ch. 4 - Prob. 172PCh. 4 - A small chicken (k=0.45W/m.K,=0.1510-6m2/s) and...Ch. 4 - A potato may be approximated as a 5.7-cm-diameter...Ch. 4 - When water, as in a pond or lake, is heated by...Ch. 4 - A large chunk of tissue at 35C with a thermal...Ch. 4 - Prob. 177PCh. 4 - Citrus trees are very susceptible to cold weather,...
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
- A hole is drilled on a soft steel. The power consumed by the drill is 0.25 kW. Since this driling process takes 3 minutes, determine the amount of heat (kJ) released during the process.arrow_forwardIf a food product is being frozen in a system capable of removing 6200 kJ of thermal energy per product, with the product having a specific heat of 4.1 kJ/kg°C above the freezing temperature of -1.7°C , a latent heat of fusion of 284 kJ/kg, and the product has a specific heat of 2.2 kJ/kg°C below the freezing temperature. If 10.1 kg of product enters the system at 15°C, and exits it with a temperature of –12 °C, what percentage (to the nearest percent) of the full capability of the freezer has been used?arrow_forward"Consider a heat engine with a piston chamber that has a diameter of 30 mm, a cold reservoir at 285 K and hot reservoir at 350 K. It is also equipped with a metal can cylinder that has a volume of 0.0002 m3. What is the total volume of air in the system if the metal can cylinder is in the hot reservoir and the measured pressure and height of the piston are 103850 Pa and 60 mm, respectively?" O 4.24x10-5 m3 O 4.25x10-2 m3 O 2,42x10-4 m3 O 3.70x10-4 m3arrow_forward
- If the LHV of wood logs is 16 MJ/kg, how much energy is available for 2 kg of wood logs? If I burn all wood logs, what is the maximum energy in the heat I could obtain? If 30% of heat can be changed to electricity, how much electricity will be generated? If the heating value (LHV) of dry wood is 20 MJ/kg, what is the maximum energy 20 tonnes of wood could provide? If 60 % of the heat in wood could be transferred, how much heat can be transferred? If the heating value of coal is 40 MJ/kg, how much energy is available for 10 tonnes of coal? If I burn wood logs (LHV =16 MJ) to obtain the same amount of heat, how much (in tonne) of wood logs do I need to burn?arrow_forward3500J / s of energy is transferred from a heat source to the surface of the part. The heated region is circular and the heat density decreases as the radius increases. Find out whether the heat density is sufficient to melt the metal since 70% of the heat is concentrated in a circle with a diameter of 3.75 mm.arrow_forwardTwo friends, Jack and Jill, sit down to talk and enjoy a cup of coffee. When the coffee is served, Jack immediately adds a tablespoon of cream to his coffee. Jill, occupied with the discussion, waits 10 minutes before adding a tablespoon of cream, which has been kept at a constant temperature. The two friends then begin to drink their coffee. Who has the hotter coffee at that time? Assume that the cream is cooler than the air and justify your answer using Newton’s law of cooling. Please help solve this problem! Thank you!arrow_forward
- Two friends, Jack and Jill, sit down to talk and enjoy a cup of coffee. When the coffee is served, Jack immediately adds a tablespoon of cream to his coffee. Jill, occupied with the discussion, waits 10 minutes before adding a tablespoon of cream, which has been kept at a constant temperature. The two friends then begin to drink their coffee. Who has the hotter coffee at that time? Assume that the cream is cooler than the air and justify your answer using Newton’s law of cooling.arrow_forwardHeat transfer is of critical importance in various industrial applications, including manufacturing. During machining, both the cutting tool and the workpiece will be significantly heated by friction heating. The heating of the cutting tool will reduce the tool hardness and strength, deteriorate the cutting quality, and shorten the tool life. Therefore, it is essential to prevent the overheating of the cutting tool during machining. Coolants are an instrumental part of machining to help cool the tool and the workpiece, provide lubricant, flush away chips, and prevent corrosion. The task of this project is to design the coolant to maintain the maximum machine tool temperature below 100 °C during the side milling process. As shown in the figure below, the machine tool has a diameter of 10 mm (D) and a length of 5 cm. The tool material is M2 high speed tool steel (T11302) and the workpiece is aluminum 6061. The spindle speed (w) is 2000 RPM and the cutting speed (v) is 50 mm/min. The feed…arrow_forwardWhat is the effect of wind shear on thermals?arrow_forward
- On a 5 day wilderness expedition you'll need to heat 3.0kg of water to the boiling point each day. The air temperature will average 25°C. You have available canisters of compressed propane C3H8 fuel, which you'll burn to heat the water. Each canister has 100.g of propane in it. What is the minimum number of fuel canisters you must bring? The standard heat of formation of propane at 25°C is −103.85/kJmol.arrow_forwardCalculate the temperature in an unheated space (Tunc) adjacent to a conditioned room with three (3) common surface areas of 175-ft2, 190-ft2, and 210-ft² with an overall heat transfer coefficient of 0.21, 0.27, and 0.32 Btu/h-Ft2 °F, respectively. The surface areas of the unheated space exposed to the outdoors are 175-ft² and 210-ft² with corresponding overall heat transfer coefficients of 0.21 and 0.40 Btu/h- Ft².°F. The sixth (6th) surface is on the ground and can be neglected for this example as can be the effect of any outdoor air entering the space. Inside & outside design reference temperatures are 70°F & -10°F, respectively. Tunc = 37°F Tunc = 36°F Tunc = 30°F Tunc = 35°Farrow_forwardA food product with 82% moisture content is being frozen. Estimate the specific heat of the product at -8°C when 82% of the water is in a frozen state. The specific heat of dry product solid is 2.5 kJ/(kg °C). Assume specific heat of water at -10°C is similar to specific heat of water at 0°C.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University Press
Mechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSON
Thermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEY
Mechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage Learning
Engineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license