HEAT&MASS TRANSF. (LL) W/CONNECT<CUSTOM>
6th Edition
ISBN: 9781266141652
Author: CENGEL
Publisher: MCG
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 1, Problem 35CP
Why do we characterize the heat conduction ability of insulators in terms of their apparent thermal conductivity instead of ordinary thermal conductivity?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
aversity of Baoyion
aculty of Engineering-AIMusyab
Automobile Eng. Dep.
Year: 2022-2023,
st Course, 1st Attempt
Stage: 3rd
Subject: Heat Transfer I
Date: 2023\01\23- Monday
Time: 3 Hours
Q4: A thick slab of copper initially at a uniform temperature of 20°C is suddenly exposed
to radiation at one surface such that the net heat flux is maintained at a constant value of
3×105 W/m². Using the explicit finite-difference techniques with a space increment of Ax
=
= 75 mm, determine the temperature at the irradiated surface and at an interior point that is
150 mm from the surface after 2 min have elapsed.
Q5:
(12.5 M)
A) A steel bar 2.5 cm square and 7.5 cm long is initially at a temperature of 250°C. It is
immersed in a tank of oil maintained at 30°C. The heat-transfer coefficient is 570 W/m². C.
Calculate the temperature in the center of the bar after 3 min.
B) Air at 90°C and atmospheric pressure flows over a horizontal flat plate at 60 m/s. The
plate is 60 cm square and is maintained at a…
University of Baby on
Faculty of Engineering-AIMusyab
Automobile Eng. Dep.
Year: 2022-2023.
1 Course, 1" Attempt
Stage 3
Subject Heat Transfer I
Date: 2023 01 23- Monday
Time: 3 Hours
Notes:
Q1:
•
•
Answer four questions only
Use Troles and Appendices
A) A flat wall is exposed to an environmental temperature of 38°C. The wall is covered
with a layer of insulation 2.5 cm thick whose thermal conductivity is 1.4 W/m. C,
and the temperature of the wall on the inside of the insulation is 315°C. The wall
loses heat to the environment by convection. Compute the value of the convection
heat-transfer coefficient that must be maintained on the outer surface of the
insulation to ensure that the outer-surface temperature does not exceed 41°C.
B) A vertical square plate, 30 cm on a side, is maintained at 50°C and exposed to room
air at 20°C. The surface emissivity is 0.8. Calculate the total heat lost by both sides
of the plate.
(12.5 M)
Q2: An aluminum fin 1.5 mm thick is placed on a circular tube…
Solve using graphical method and analytical method, only expert should solve
Chapter 1 Solutions
HEAT&MASS TRANSF. (LL) W/CONNECT<CUSTOM>
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
- Need helparrow_forwardY F1 α В X F2 You and your friends are planning to move the log. The log. needs to be moved straight in the x-axis direction and it takes a combined force of 2.9 kN. You (F1) are able to exert 610 N at a = 32°. What magnitude (F2) and direction (B) do you needs your friends to pull? Your friends had to pull at: magnitude in Newton, F2 = direction in degrees, ẞ = N degarrow_forwardProblem 1 8 in. in. PROBLEM 15.109 Knowing that at the instant shown crank BC has a constant angular velocity of 45 rpm clockwise, determine the acceleration (a) of Point A, (b) of Point D. 8 in. Answer: convert rpm to rad/sec first. (a). -51.2j in/s²; (b). 176.6 i + 50.8 j in/s²arrow_forward
- Problem 4 The semicircular disk has a radius of 0.4 m. At one instant, when 0-60°, it is rotating counterclockwise at 0-4 rad/s, which is increasing in the same direction at 1 rad/s². Find the velocity and acceleration of point B at this instant. (Suggestion: Set up relative velocity and relative acceleration that way you would for a no-slip disk; remember what I told you to memorize on the first day of class.) (Answer: B = −2.98î - 0.8ĵ m/s, ãB = 2.45î - 5.74ĵ m/s²) B 0.4 m y Xarrow_forwardA C C 2r A 2r B B (a) (b) Problem 3 Refer to (b) of the figure shown above. The disk OA is now rolling with no slip at a constant angular velocity of w. Find the angular velocity and angular acceleration of link AB and BC. (Partial Answers: WBC = 2wk, AB = w²k)arrow_forwardProblem 2 Refer to (a) of the figure shown below, where the disk OA rotates at a constant angular velocity of w. Find the angular velocity and angular acceleration of link AB and link BC. (Partial Answers: WBC = wk, AB = w²k) A 2r C B (a) A 2r B (b)arrow_forward
- Example Two rotating rods are connected by slider block P. The rod attached at A rotates with a constant clockwise angular velocity WA. For the given data, determine for the position shown (a) the angular velocity of the rod attached at B, (b) the relative velocity of slider block P with respect to the rod on which it slides. b = 8 in., w₁ = 6 rad/s. Given: b = 8 in., WA = 6 rad/s CW constant Find: (a). WBE (b). Vp/Frame E 60° 20° Barrow_forwardY F1 α В X F2 You and your friends are planning to move the log. The log. needs to be moved straight in the x-axis direction and it takes a combined force of 2.9 kN. You (F1) are able to exert 610 N at a = 32°. What magnitude (F2) and direction (B) do you needs your friends to pull? Your friends had to pull at: magnitude in Newton, F2 = direction in degrees, ẞ = N degarrow_forward100 As a spring is heated, its spring constant decreases. Suppose the spring is heated and then cooled so that the spring constant at time t is k(t) = t sin + N/m. If the mass-spring system has mass m = 2 kg and a damping constant b = 1 N-sec/m with initial conditions x(0) = 6 m and x'(0) = -5 m/sec and it is subjected to the harmonic external force f (t) = 100 cos 3t N. Find at least the first four nonzero terms in a power series expansion about t = 0, i.e. Maclaurin series expansion, for the displacement: • Analytically (hand calculations) Creating Simulink Model Plot solutions for first two, three and four non-zero terms as well as the Simulink solution on the same graph for the first 15 sec. The graph must be fully formatted by code.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.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