THERMODYNAMICS(SI UNITS,INTL.ED)EBOOK>I
8th Edition
ISBN: 9781307434316
Author: CENGEL
Publisher: INTER MCG
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 2.8, Problem 38P
On a hot summer day, a student turns his fan on when he leaves his room in the morning. When he returns in the evening, will the room be warmer or cooler than the neighboring rooms? Why? Assume all the doors and windows are kept closed.
Expert Solution & Answer

Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
handwritten-solutions, please!
No use chatgpt
Problem 6 (Optional, extra 6 points)
150 mm
150 mm
120 mm
80 mm
60 mm
PROBLEM 18.103
A 2.5 kg homogeneous disk of radius 80 mm rotates with an
angular velocity ₁ with respect to arm ABC, which is welded
to a shaft DCE rotating as shown at the constant rate
w212 rad/s. Friction in the bearing at A causes ₁ to
decrease at the rate of 15 rad/s². Determine the dynamic
reactions at D and E at a time when ₁ has decreased to
50 rad/s.
Answer:
5=-22.01 +26.8} N
E=-21.2-5.20Ĵ N
Chapter 2 Solutions
THERMODYNAMICS(SI UNITS,INTL.ED)EBOOK>I
Ch. 2.8 - What is total energy? Identify the different forms...Ch. 2.8 - List the forms of energy that contribute to the...Ch. 2.8 - How are heat, internal energy, and thermal energy...Ch. 2.8 - What is mechanical energy? How does it differ from...Ch. 2.8 - Natural gas, which is mostly methane CH4, is a...Ch. 2.8 - Portable electric heaters are commonly used to...Ch. 2.8 - Prob. 7PCh. 2.8 - Prob. 8PCh. 2.8 - 2–9E Calculate the total potential energy, in Btu,...Ch. 2.8 - Prob. 10P
Ch. 2.8 - Prob. 11PCh. 2.8 - At a certain location, wind is blowing steadily at...Ch. 2.8 - A water jet that leaves a nozzle at 60 m/s at a...Ch. 2.8 - Prob. 14PCh. 2.8 - Prob. 15PCh. 2.8 - Consider a river flowing toward a lake at an...Ch. 2.8 - When is the energy crossing the boundaries of a...Ch. 2.8 - Consider an automobile traveling at a constant...Ch. 2.8 - A gas in a pistoncylinder device is compressed,...Ch. 2.8 - A room is heated by an iron that is left plugged...Ch. 2.8 - A room is heated as a result of solar radiation...Ch. 2.8 - Prob. 23PCh. 2.8 - A small electrical motor produces 5 W of...Ch. 2.8 - Prob. 25PCh. 2.8 - 2–26C Lifting a weight to a height of 20 m takes...Ch. 2.8 - Prob. 27PCh. 2.8 - Prob. 28PCh. 2.8 - Prob. 29PCh. 2.8 - Prob. 30PCh. 2.8 - Prob. 31PCh. 2.8 - Prob. 32PCh. 2.8 - Prob. 33PCh. 2.8 - A ski lift has a one-way length of 1 km and a...Ch. 2.8 - The engine of a 1500-kg automobile has a power...Ch. 2.8 - Prob. 36PCh. 2.8 - What are the different mechanisms for transferring...Ch. 2.8 - On a hot summer day, a student turns his fan on...Ch. 2.8 - Prob. 39PCh. 2.8 - A vertical pistoncylinder device contains water...Ch. 2.8 - At winter design conditions, a house is projected...Ch. 2.8 - A water pump increases the water pressure from 15...Ch. 2.8 - Prob. 43PCh. 2.8 - Prob. 44PCh. 2.8 - A university campus has 200 classrooms and 400...Ch. 2.8 - Prob. 46PCh. 2.8 - Consider a room that is initially at the outdoor...Ch. 2.8 - Prob. 48PCh. 2.8 - 2-49 The 60-W fan of a central heating system is...Ch. 2.8 - Prob. 50PCh. 2.8 - An escalator in a shopping center is designed to...Ch. 2.8 - Prob. 52PCh. 2.8 - How is the combined pumpmotor efficiency of a pump...Ch. 2.8 - Prob. 54PCh. 2.8 - Can the combined turbinegenerator efficiency be...Ch. 2.8 - Consider a 2.4-kW hooded electric open burner in...Ch. 2.8 - Prob. 57PCh. 2.8 - Prob. 58PCh. 2.8 - Prob. 59PCh. 2.8 - A geothermal pump is used to pump brine whose...Ch. 2.8 - Prob. 62PCh. 2.8 - Prob. 63PCh. 2.8 - The water in a large lake is to be used to...Ch. 2.8 - A 7-hp (shaft) pump is used to raise water to an...Ch. 2.8 - At a certain location, wind is blowing steadily at...Ch. 2.8 - Reconsider Prob. 265. Using appropriate software,...Ch. 2.8 - Water is pumped from a lake to a storage tank 15 m...Ch. 2.8 - Prob. 69PCh. 2.8 - A hydraulic turbine has 85 m of elevation...Ch. 2.8 - Prob. 71PCh. 2.8 - Water is pumped from a lower reservoir to a higher...Ch. 2.8 - Prob. 73PCh. 2.8 - An oil pump is drawing 44 kW of electric power...Ch. 2.8 - How does energy conversion affect the environment?...Ch. 2.8 - What is acid rain? Why is it called a rain? How do...Ch. 2.8 - Why is carbon monoxide a dangerous air pollutant?...Ch. 2.8 - What is the greenhouse effect? How does the excess...Ch. 2.8 - What is smog? What does it consist of? How does...Ch. 2.8 - Prob. 80PCh. 2.8 - Consider a household that uses 14,000 kWh of...Ch. 2.8 - When a hydrocarbon fuel is burned, almost all of...Ch. 2.8 - Prob. 83PCh. 2.8 - A typical car driven 20,000 km a year emits to the...Ch. 2.8 - What are the mechanisms of heat transfer?Ch. 2.8 - Which is a better heat conductor, diamond or...Ch. 2.8 - How does forced convection differ from natural...Ch. 2.8 - What is a blackbody? How do real bodies differ...Ch. 2.8 - Define emissivity and absorptivity. What is...Ch. 2.8 - Does any of the energy of the sun reach the earth...Ch. 2.8 - The inner and outer surfaces of a 5-m 6-m brick...Ch. 2.8 - The inner and outer surfaces of a 0.5-cm-thick 2-m...Ch. 2.8 - Reconsider Prob. 292. Using appropriate software,...Ch. 2.8 - Prob. 94PCh. 2.8 - Prob. 95PCh. 2.8 - Prob. 96PCh. 2.8 - Prob. 97PCh. 2.8 - For heat transfer purposes, a standing man can be...Ch. 2.8 - Prob. 99PCh. 2.8 - Prob. 100PCh. 2.8 - A 1000-W iron is left on the ironing board with...Ch. 2.8 - A 7-cm-external-diameter, 18-m-long hot-water pipe...Ch. 2.8 - A thin metal plate is insulated on the back and...Ch. 2.8 - Reconsider Prob. 2103. Using appropriate software,...Ch. 2.8 - The outer surface of a spacecraft in space has an...Ch. 2.8 - Prob. 106PCh. 2.8 - A hollow spherical iron container whose outer...Ch. 2.8 - Consider a vertical elevator whose cabin has a...Ch. 2.8 - Consider a homeowner who is replacing his...Ch. 2.8 - Prob. 110RPCh. 2.8 - Prob. 111RPCh. 2.8 - Prob. 112RPCh. 2.8 - 2–113 The U.S. Department of Energy estimates that...Ch. 2.8 - Prob. 114RPCh. 2.8 - Prob. 115RPCh. 2.8 - Prob. 116RPCh. 2.8 - Prob. 117RPCh. 2.8 - Consider a TV set that consumes 120 W of electric...Ch. 2.8 - Water is pumped from a 200-ft-deep well into a...Ch. 2.8 - Prob. 120RPCh. 2.8 - Prob. 121RPCh. 2.8 - In a hydroelectric power plant, 65 m3/s of water...Ch. 2.8 - The demand for electric power is usually much...Ch. 2.8 - The pump of a water distribution system is powered...Ch. 2.8 - On a hot summer day, the air in a well-sealed room...Ch. 2.8 - Prob. 126FEPCh. 2.8 - A 2-kW electric resistance heater in a room is...Ch. 2.8 - A 900-kg car cruising at a constant speed of 60...Ch. 2.8 - Prob. 129FEPCh. 2.8 - Prob. 130FEPCh. 2.8 - Prob. 131FEPCh. 2.8 - A 2-kW pump is used to pump kerosene ( = 0.820...Ch. 2.8 - Prob. 133FEPCh. 2.8 - Prob. 134FEPCh. 2.8 - Prob. 135FEPCh. 2.8 - Prob. 136FEPCh. 2.8 - Prob. 137FEPCh. 2.8 - Heat is transferred steadily through a...Ch. 2.8 - The roof of an electrically heated house is 7 m...
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
A nozzle at A discharges water with an initial velocity of 36 ft/s at an angle with the horizontal. Determine ...
Vector Mechanics For Engineers
The solid steel shaft AC has a diameter of 25 mm and is supported by smooth bearings at D and E. It is coupled ...
Mechanics of Materials (10th Edition)
Why is the study of database technology important?
Database Concepts (8th Edition)
What are the design issues for character string types?
Concepts Of Programming Languages
How are relationships between tables expressed in a relational database?
Modern Database Management
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
- Problem 1. Two uniform rods AB and CE, each of weight 3 lb and length 2 ft, are welded to each other at their midpoints. Knowing that this assembly has an angular velocity of constant magnitude c = 12 rad/s, determine: (1). the magnitude and direction of the angular momentum HD of the assembly about D. (2). the dynamic reactions (ignore mg) at the bearings at A and B. 9 in. 3 in. 03 9 in. 3 in. Answers: HD = 0.162 i +0.184 j slug-ft²/s HG = 2.21 k Ay =-1.1 lb; Az = 0; By = 1.1 lb; B₂ = 0.arrow_forwardProblem 5 (Optional, extra 6 points) A 6-lb homogeneous disk of radius 3 in. spins as shown at the constant rate w₁ = 60 rad/s. The disk is supported by the fork-ended rod AB, which is welded to the vertical shaft CBD. The system is at rest when a couple Mo= (0.25ft-lb)j is applied to the shaft for 2 s and then removed. Determine the dynamic reactions at C and D before and after the couple has been removed at 2 s. 4 in. C B Mo 5 in 4 in. Note: 2 rotating around CD induced by Mo is NOT constant before Mo is removed. and ₂ (two unknowns) are related by the equation: ₂ =0+ w₂t 3 in. Partial Answer (after Mo has been removed): C-7.81+7.43k lb D -7.81 7.43 lbarrow_forwardProblem 4. A homogeneous disk with radius and mass m is mounted on an axle OG with length L and a negligible mass. The axle is pivoted at the fixed-point O, and the disk is constrained to roll on a horizontal surface. The disk rotates counterclockwise at the constant rate o₁ about the axle. (mg must be included into your calculation) (a). Calculate the linear velocity of G and indicate it on the figure. (b). Calculate ₂ (constant), which is the angular velocity of the axle OG around the vertical axis. (c). Calculate the linear acceleration ā of G and indicate it on the figure. (d). Determine the force (assumed vertical) exerted by the floor on the disk (e). Determine the reaction at the pivot O. 1 Answers: N = mg +mr(r/L)² @² |j mr w IIG C R L i+ 2L =arrow_forward
- Problem 2. The homogeneous disk of weight W = 6 lb rotates at the constant rate co₁ = 16 rad/s with respect to arm ABC, which is welded to a shaft DCE rotating at the constant rate 2 = 8 rad/s. Assume the rod weight is negligible compared to the disk. Determine the dynamic reactions at D and E (ignore mg). Answers: D=-7.12ĵ+4.47k lb r-8 in. 9 in. B D E=-1.822+4.47 lb 9 in. E 12 in. 12 in. xarrow_forwardProblem 3. Each of the right angle rods has a mass of 120 g and is welded to the shaft, which rotates at a steady speed of 3600 rpm. Ignore the weight of the shaft AB. Find the bearing dynamic reaction at A due to the dynamic imbalance of the shaft. (ignore mgs) 100 N A 100 100 100 100 100 (Dimensions in millimeters) Answer: A=-8521-426j N Barrow_forwardThermodynamics. Need help solving this. Step by step with unitsarrow_forward
- Quiz/An eccentrically loaded bracket is welded to the support as shown in Figure below. The load is static. The weld size for weld w1 is h1 = 4mm, for w2 h2=6mm, and for w3 is h3 -6.5 mm. Determine the safety factor (S.f) for the welds. F=29 kN. Use an AWS Electrode type (E100xx). 163 mm 133 mm 140 mm w3 wiarrow_forwardE W X FO FB F10 F11 F12 Home Q: Consider the square of Figure below.The left face is maintained at 100°C and the top face at 500°C, while the other two faces are exposed to an environment at1 00°C, h=10 W/m². C and k=10 W/m.°C. The block is 1 m square. Compute the temperature of the various nodes as indicated in Figure below and the heat flows at the boundaries. T= 500°C Alt Explain to me in detail how to calculate the matrix in the Casio calculator type (fx-991ES plus) T= 100°C 1 2 4 7 1 m- 3 1 m 5 6 T= 100°C 8 9arrow_forwardWhich of the following sequences converge and which diverge? 1) a₁ = 2+(0.1)" 1-2n 2) a = 1+2n 1/n 3 16) a = n In n 17) an = n 1/n 1-5n4 3) an = n² +8n³ 18) an = √4" n n² -2n+1 n! 20) a = 4) an = 106 5) n-1 a₁ =1+(-1)" n+1 a-(+) (1-4) 6) = 7) a = 2n (-1)"+1 2n-1 21) an = n -A" 1/(Inn) 3n+1 22) a = 3n-1 1/n x" 23) a = , x>0 2n+1 3" x 6" 24) a = 2™" xn! 2n 8) a = n+1 πT 1 9) a„ = sin +- 2 n sin n 10) an = n 25) a = tanh(n) 26) a = 2n-1 27) a = tan(n) 1 -sin n n 11) a = 2" 28) an == " 1 + 2" In(n+1) 12) a = n (In n) 200 29) a = n 13) a = 8/n 14) a 1+ =(1+²)" 15) an 7 n = 10n 30) an-√√n²-n 1"1 31) adx nixarrow_forward
- A steel alloy contains 95.7 wt% Fe, 4.0 wt% W, and 0.3 wt% C.arrow_forwardb. A horizontal cantilever of effective length 3a, carries two concentrated loads W at a distance a from the fixed end and W' at a distance a from the free end. Obtain a formula for the maximum deflection due to this loading using Mohr's method. If the cantilever is 250 mm by 150mm steel I beam, 3 m long having a second moment of area I as 8500 cm4, determine W and W'to give a maximum deflection of 6 mm when the maximum stress due to bending is 90 Mpa. Take Young's modulus of material E as 185 Gpa.arrow_forwardWhich of the following sequences converge and which diverge? 1/n 1) a₁ = 2+(0.1)" 3 16) a = n 1-2n 2) a = In n 1+2n 17) an = 1/n n 1-5n4 3) an = n² +8n³ 18) an = √4" n n! n² -2n+1 20) a = 4) an = 106 5) n-1 a₁ =1+(-1)" n+1 a-(+) (1-4) 6) = 7) a = 2n (-1)"+1 2n-1 21) an = n -A" 1/(Inn) 3n+1 22) a = 3n-1 1/n x" 23) a = , x>0 2n+1 3" x 6" 24) a = 2™" xn! 2n 8) a = n+1 πT 1 9) a„ = sin +- 2 n sin n 10) an = n 25) a = tanh(n) 26) a = 2n-1 27) a = tan(n) 1 -sin n n 11) a = 2" 28) an == " 1 + 2" In(n+1) 12) a = n (In n) 200 29) a = n 13) a = 8/n 14) a 1+ =(1+²)" 15) an 7 n = 10n 30) an-√√n²-n 1"1 31) adx nixarrow_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 LearningPrinciples 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