Thermodynamics: An Engineering Approach
8th Edition
ISBN: 9780073398174
Author: Yunus A. Cengel Dr., Michael A. Boles
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 3.8, Problem 8P
A househusband is cooking beef stew for his family in a pan that is (a) uncovered, (b) covered with a light lid, and (c) covered with a heavy lid. For which case will the cooking time be the shortest? Why?
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
2 A metal block of mass m = 10 kg is sliding along a frictionless surface with an initial speed
Vo, as indicated below. The block then slides above an electromagnetic brake that applies a
force FEB to the block, opposing its motion. The magnitude of the electromagnetic force
varies quadratically with the distance moved along the brake (x):
10
FEB = kx²,
with k
= 5
N
m²
V₁ = 8 m/s
m = 10 kg
FEB
Frictionless surface
Electromagnetic brake
⇒x
Determine how far the block slides along the electromagnetic brake before stopping, in m.
Q1: Determine the length, angle of contact, and width of a 9.75 mm thick
leather belt required to transmit 15 kW from a motor running at 900 r.p.m. The
diameter of the driving pulley of the motor is 300 mm. The driven pulley runs at
300 r.p.m. and the distance between the centers of two pulleys is 3 meters. The
density of the leather is 1000 kg/m³. The maximum allowable stress in the
leather is 2.5 MPa. The coefficient of friction between the leather and pulley is
0.3. Assume open belt drive.
5. A 15 kW and 1200 r.p.m. motor drives a compressor at 300 r.p.m. through a pair of spur gears having
20° stub teeth. The centre to centre distance between the shafts is 400 mm. The motor pinion is made
of forged steel having an allowable static stress as 210 MPa, while the gear is made of cast steel
having allowable static stress as 140 MPa. Assuming that the drive operates 8 to 10 hours per day
under light shock conditions, find from the standpoint of strength,
1. Module; 2. Face width and 3. Number of teeth and pitch circle diameter of each gear.
Check the gears thus designed from the consideration of wear. The surface endurance limit may be
taken as 700 MPa. [Ans. m = 6 mm; b= 60 mm; Tp=24; T=96; Dp = 144mm; DG = 576 mm]
Chapter 3 Solutions
Thermodynamics: An Engineering Approach
Ch. 3.8 - Is iced water a pure substance? Why?Ch. 3.8 - What is the difference between saturated vapor and...Ch. 3.8 - 3–3C Is there any difference between the...Ch. 3.8 - 3–4C Why are the temperature and pressure...Ch. 3.8 - Is it true that water boils at higher temperature...Ch. 3.8 - What is the difference between the critical point...Ch. 3.8 -
3–7C Is it possible to have water vapor at ?
Ch. 3.8 - A househusband is cooking beef stew for his family...Ch. 3.8 - In what kind of pot will a given volume of water...Ch. 3.8 - It is well known that warm air in a cooler...
Ch. 3.8 - Does the amount of heat absorbed as 1 kg of...Ch. 3.8 - Does the reference point selected for the...Ch. 3.8 - What is the physical significance of hfg? Can it...Ch. 3.8 - Does hfg change with pressure? How?Ch. 3.8 - Is it true that it takes more energy to vaporize 1...Ch. 3.8 - What is quality? Does it have any meaning in the...Ch. 3.8 - Which process requires more energy: completely...Ch. 3.8 - In the absence of compressed liquid tables, how is...Ch. 3.8 - Prob. 19PCh. 3.8 - Complete this table for H2O:Ch. 3.8 - Prob. 21PCh. 3.8 - Complete this table for H2O:Ch. 3.8 - Complete this table for H2O:Ch. 3.8 - Prob. 26PCh. 3.8 - Complete this table for refrigerant-134a:Ch. 3.8 - A 1.8-m3 rigid tank contains steam at 220C....Ch. 3.8 - A pistoncylinder device contains 0.85 kg of...Ch. 3.8 - Prob. 30PCh. 3.8 -
3–31 10-kg of R-134a fill a 1.348-m3 rigid...Ch. 3.8 - Prob. 32PCh. 3.8 - Refrigerant-134a at 200 kPa and 25C flows through...Ch. 3.8 - Prob. 34PCh. 3.8 - The temperature in a pressure cooker during...Ch. 3.8 - Prob. 36PCh. 3.8 -
3–37E One pound-mass of water fills a 2.4264-ft3...Ch. 3.8 - Prob. 38PCh. 3.8 - Water is to be boiled at sea level in a...Ch. 3.8 - Repeat Prob. 340 for a location at an elevation of...Ch. 3.8 - 10 kg of R-134a at 300 kPa fills a rigid container...Ch. 3.8 - 100 kg of R-134a at 200 kPa are contained in a...Ch. 3.8 - Water initially at 200 kPa and 300C is contained...Ch. 3.8 -
3–44 Saturated steam coming off the turbine of a...Ch. 3.8 - Prob. 45PCh. 3.8 - Prob. 46PCh. 3.8 - Water is being heated in a vertical pistoncylinder...Ch. 3.8 - Prob. 49PCh. 3.8 - A rigid tank with a volume of 1.8 m3 contains 40...Ch. 3.8 - A pistoncylinder device contains 0.005 m3 of...Ch. 3.8 -
3–53E A 5-ft3 rigid tank contains 5 lbm of water...Ch. 3.8 - A 5-ft3 rigid tank contains a saturated mixture of...Ch. 3.8 - Superheated water vapor at 180 psia and 500F is...Ch. 3.8 - Prob. 57PCh. 3.8 - 3–58 A rigid tank contains water vapor at 250°C...Ch. 3.8 - A pistoncylinder device initially contains 1.4 kg...Ch. 3.8 - How much error would one expect in determining the...Ch. 3.8 - Prob. 61PCh. 3.8 -
3–62 A rigid vessel contains 8 kg of...Ch. 3.8 - A rigid tank initially contains 1.4 kg saturated...Ch. 3.8 - A pistoncylinder device initially contains 50 L of...Ch. 3.8 - Under what conditions is the ideal-gas assumption...Ch. 3.8 - Prob. 66PCh. 3.8 - Propane and methane are commonly used for heating...Ch. 3.8 - A 400-L rigid tank contains 5 kg of air at 25C....Ch. 3.8 - Prob. 69PCh. 3.8 - Prob. 70PCh. 3.8 - The pressure gage on a 2.5-m3 oxygen tank reads...Ch. 3.8 - A spherical balloon with a diameter of 9 m is...Ch. 3.8 - Reconsider Prob. 373. Using appropriate software,...Ch. 3.8 - Prob. 74PCh. 3.8 - Prob. 75PCh. 3.8 - A rigid tank whose volume is unknown is divided...Ch. 3.8 - Prob. 77PCh. 3.8 - Prob. 78PCh. 3.8 - Prob. 79PCh. 3.8 - Prob. 80PCh. 3.8 - Prob. 81PCh. 3.8 - Determine the specific volume of superheated water...Ch. 3.8 - Determine the specific volume of superheated water...Ch. 3.8 - Prob. 85PCh. 3.8 - Prob. 86PCh. 3.8 - Prob. 87PCh. 3.8 - Prob. 88PCh. 3.8 - Prob. 89PCh. 3.8 - Prob. 90PCh. 3.8 - Carbon dioxide gas enters a pipe at 3 MPa and 500...Ch. 3.8 - A 0.016773-m3 tank contains 1 kg of...Ch. 3.8 - What is the physical significance of the two...Ch. 3.8 - A 3.27-m3 tank contains 100 kg of nitrogen at 175...Ch. 3.8 - Prob. 95PCh. 3.8 - Refrigerant-134a at 400 psia has a specific volume...Ch. 3.8 - Nitrogen at 150 K has a specific volume of...Ch. 3.8 - A 1-m3 tank contains 2.841 kg of steam at 0.6 MPa....Ch. 3.8 - Prob. 102PCh. 3.8 - Prob. 103PCh. 3.8 - On a certain day, the temperature and relative...Ch. 3.8 - Prob. 105PCh. 3.8 - Consider two rooms that are identical except that...Ch. 3.8 - A thermos bottle is half-filled with water and is...Ch. 3.8 - Prob. 108RPCh. 3.8 - The combustion in a gasoline engine may be...Ch. 3.8 - A tank contains argon at 600C and 200 kPa gage....Ch. 3.8 - Prob. 111RPCh. 3.8 - Prob. 112RPCh. 3.8 - A rigid tank with a volume of 0.117 m3 contains 1...Ch. 3.8 - Prob. 114RPCh. 3.8 - Ethane at 10 MPa and 100C is heated at constant...Ch. 3.8 - Prob. 116RPCh. 3.8 - A 10-kg mass of superheated refrigerant-134a at...Ch. 3.8 - A 4-L rigid tank contains 2 kg of saturated...Ch. 3.8 - The gage pressure of an automobile tire is...Ch. 3.8 - Prob. 120RPCh. 3.8 - Steam at 400C has a specific volume of 0.02 m3/kg....Ch. 3.8 - A tank whose volume is unknown is divided into two...Ch. 3.8 - Prob. 123RPCh. 3.8 - Prob. 124RPCh. 3.8 - Prob. 125RPCh. 3.8 - A tank contains helium at 37C and 140 kPa gage....Ch. 3.8 - Prob. 127RPCh. 3.8 - Prob. 131RPCh. 3.8 - Consider an 18-m-diameter hot-air balloon that,...Ch. 3.8 - Prob. 134FEPCh. 3.8 - Water is boiled at 1 atm pressure in a coffeemaker...Ch. 3.8 - Prob. 136FEPCh. 3.8 - Prob. 137FEPCh. 3.8 - Water is boiled in a pan on a stove at sea level....Ch. 3.8 - Prob. 139FEPCh. 3.8 - Consider a sealed can that is filled with...Ch. 3.8 - A rigid tank contains 2 kg of an ideal gas at 4...Ch. 3.8 - The pressure of an automobile tire is measured to...
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
- 4. G A micarta pinion rotating at 1200 r.p.m. is to transmit 1 kW to a cast iron gear at a speed of 192 r.p.m. Assuming a starting overload of 20% and using 20° full depth involute teeth, determine the module, number of teeth on the pinion and gear and face width. Take allowable static strength for micarta as 40 MPa and for cast iron as 53 MPa. Check the pair in wear.arrow_forwardI want to solve these choicesarrow_forward2. A spur gear made of bronze drives a mid steel pinion with angular velocity ratio of 32: 1. The pressure angle is 14½. It transmits 5 kW at 1800 r.p.m. of pinion. Considering only strength, design the smallest diameter gears and find also necessary face width. The number of teeth should not be less than 15 teeth on either gear. The elastic strength of bronze may be taken as 84 MPa and of steel as 105 MPa. Lewis factor for 14½½ pressure angle may be taken 0.684 0.124 y = No. of teeth as [Ans. m 3 mm; b= 35 mm; Dp = 48 mm; D= 168 mm]arrow_forward
- Q2. Determine the safety factors for the bracket rod shown in Figure 2 based on both the distortion-energy theory and the maximum shear theory and compare them. Given: The material is 2024-T4 aluminum with a yield strength of 47 000 psi. The rod length /= 6 in. and arm a = 8 in. The rod outside diameter od 1.5 in., id = 1 in, h=2 in., t=0.5 in., Load F= 1000 lb. Assumptions: The load is static and the assembly is at room temperature. Consider shear due to transverse loading as well as other stresses. (Note: solve in SI units) wall tube Figure 2 armarrow_forwardThe question has been set up with all the cuts needed to accurately derive expressions for V(x) and M(x). Using the cuts free body diagrams set up below, derive expressions for V(x) and M(x). If you use the method of cuts then validate your answers using calculus or vice versa.arrow_forwardIt is required to treat 130 kmol/hr of chloroform-air feed gas mixture that contains 12% chloroform. It is required to remove 93% of chloroform using 150 kmol/hr of solvent that contains 99.6% water and 0.4% chloroform. The cross sectional area of the column is 0.8 m². Calculate the column height using the following data; kx'.a = 1.35 (kmol/m³.s (Ax)), and ky'.a = 0.06 (kmol/m³.s (Ay)), kx/ky = 1.35, and the equilibrium data are: X 0 0.0133 0.033 y 0 0.01 0.0266 0.049 0.064 0.0747 0.0933 0.1053 0.0433 0.06 0.0733 0.111 0.1 0.12 0.14arrow_forward
- ४ B: Find the numerical solution for the 2D equation below and calculate the temperature values for each grid point shown in Fig. 2 (show all steps). (Do only one trail using following initial values and show the final matrix) [T1] T₂ T3 [T] 1 = [0] 0 0 d dx dx) (ka)+4(ka) = dy -20xy, k = 1 + 0.3 T ge L=3cm, 4x= Ay B.Cs.: at x=0=LT=0°C at y=0-L T=10°C Fig. (2)arrow_forward: +0 العنوان use only Two rods fins) having same dimensions, one made orass (k = 85 Wm K) and the mer of copper (k = 375 W/m K), having of their ends inserted into a furna. At a section 10.5 cm a way from furnace, the temperature of brass rod 120 Find the distance at which the ame temperature would be reached in the per rod ? both ends are ex osed to the same environment. ns 2.05 ۲/۱ ostrararrow_forwardFor the beam show below, draw A.F.D, S.F.D, B.M.D 6 kN/m 1 M B. 3 M Marrow_forward
- 1. Two long rods of the same diameter-one made of brass (k=85w/m.k) and the other made of copper (k=375 w/m.k) have one of their ends inserted into a furnace (as shown in the following figure). Both rods are exposed to the same environment. At a distance of 105 mm from the furnace, the temperature of the brass rod is 120°C. At what distance from the furnace will the same temperature be reached in the copper rod? Furnace 105 mm T₁ Brass rod ⑪ h Too- x2- Ti Copper rodarrow_forward: +0 العنوان use only Two rods fins) having same dimensions, one made orass (k = 85 Wm K) and the mer of copper (k = 375 W/m K), having of their ends inserted into a furna. At a section 10.5 cm a way from furnace, the temperature of brass rod 120 Find the distance at which the ame temperature would be reached in the per rod ? both ends are ex osed to the same environment. ns 2.05 ۲/۱ ostrararrow_forwardمشر on ۲/۱ Two rods (fins) having same dimensions, one made of brass(k=85 m K) and the other of copper (k = 375 W/m K), having one of their ends inserted into a furnace. At a section 10.5 cm a way from the furnace, the temperature brass rod 120°C. Find the distance at which the same temperature would be reached in the copper rod ? both ends are exposed to the same environment. 22.05 ofthearrow_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
Thermodynamics: Maxwell relations proofs 1 (from ; Author: lseinjr1;https://www.youtube.com/watch?v=MNusZ2C3VFw;License: Standard Youtube License