HEAT+MASS TRANSFER (LL)-W/ACCESS
6th Edition
ISBN: 9781265879631
Author: CENGEL
Publisher: MCG CUSTOM
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Chapter 1, Problem 81P
Two surfaces, one highly polished and the other heavily oxidized, are found to be emitting the same amount of energy per unit area. The highly polished surface has an emissivity of 0.1 at
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using the theorem of three moments, find all the reactions and supports, I need the calculations only
Q.5: (10 Marks) Select the correct answer (choose 10 only)
1. The forward whirling speed is ......... the static structure tilting speed.
(a) Less than
(b) Higher than
(c) equal to
2. The divergence between the forward and backward whirling speeds increases as:
(a) The rotating speed increase (b) the polar moment of inertia increases
(c) Both (a) and (b)
(d) do not change
3. Increasing the system natural frequency can be done by:
(a) add masses (b) adding braces and supports (c) increase damping
4. The amplitude of vibration due to external force can be reduced by:
(a) Increasing damping (b) Decreasing damping (c) Increasing mass
5. Tuned absorbers are used to:
(a) Shift the natural frequency (b) increase damping (c) Increase stiffness
6. Accelerometers sensors contains:
г
(a) Piezoelectric materials (b) Magnet and coil (c) coil only
7. Increasing the stiffness of the system causes:
(a) Less transmitted force (b) more transmitted force (c) Transmitted force does not
change
8. The…
Q.1: (15 Marks)
Find the first three natural frequencies and mode shapes of the axial and torsional
vibration for a steel shaft free at both ends, having a length of 3 m. Find the subsequent
axil motion if the shaft is subjected to the following initial conditions, given that E = 210
GPa, G=80 GPa, p = 7800 kg/m³:
f(x)=0
v(x) = {1
2.8
Chapter 1 Solutions
HEAT+MASS TRANSFER (LL)-W/ACCESS
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? 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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...
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