
Concept explainers
(a)
The entropy change of the computer chips.
(a)

Answer to Problem 61P
The entropy change of the computer chips is
Explanation of Solution
Write the expression for the energy balance equation.
Here, the total energy entering the system is
Substitute
Here, the mass is
Determine the heat released by the computer chips.
Here, the mass of the computer chips is
Determine the mass of the refrigerant vaporized during this heat exchange process.
Here, the saturated specific enthalpy change upon vaporization at
Determine the change in the entropy of the R-134a.
Here, the mass of the refrigerant vaporized at state 2 is
Determine the entropy change of the computer chips.
Determine the total entropy change of the entire system.
Conclusion:
Substitute 10 g for
From the Table A-11, to obtain the value of the specific enthalpy change upon vaporization, entropy of the refrigerant vaporized at state 2, entropy of the refrigerant liquid at state 2, entropy of the refrigerant liquid at state 1 at final temperature of
Substitute
Substitute
Thus, the entropy change of the computer chips is
Substitute 10 g for
Thus, the entropy change of the R-134 is
Substitute
Thus, the entropy change of the entire system is
(b)
The entropy change of the R-134.
(b)

Answer to Problem 61P
The entropy change of the R-134 is
Explanation of Solution
Determine the entropy change of the computer chips.
Conclusion:
Substitute 10 g for
Thus, the entropy change of the R-134 is
(c)
The entropy change of the entire system.
(c)

Answer to Problem 61P
The entropy change of the entire system is
Explanation of Solution
Determine the total entropy change of the entire system.
Conclusion:
Substitute
Thus, the entropy change of the entire system is
Want to see more full solutions like this?
Chapter 7 Solutions
Thermodynamics: An Engineering Approach
- Finite element analysisarrow_forwarda station is constructed on a concrete slab floor. The heat loss from the floor slab is significant, given the cold environment, and is measured to be 5 kW. The edges of the floor slab are insulated with a 60 mm thickness of cellular glass insulation. The width of this insulation at the floor slab is 0.9 m. To avoid excessive fuel consumption, the station air temperature is maintained at a slightly cool temperature of 18ºC. The station is constructed in a square shape, to keep the surface area to volume ratio low; the horizontal dimensions of the floor of the station are 20 m by 20 m. The number of occupants in the research station varies between 5 and 20, depending on the research workload.a) Determine the design outdoor temperature that was used in designing the research station.b) If the floor dimensions of the station are changed to 15 m by 25 m, would the design outdoor temperature that was used in designing the research station from part (a) change? If so, what would it be?…arrow_forwardFinite Element Analysisarrow_forward
- Finite Element Analysisarrow_forwardA small auditorium that can accommodate 30 people allows smoking. The design engineers of the auditorium assume that the smokers each are responsible for an average of 50 micrograms per minute of tobacco smoke being added to the auditorium space. The volumetric flow rate of recirculated room air is 200 cfm. Outdoor air is also supplied, and is mixed with the recirculated room air. The system has a ventilation effectiveness of 80%. In an effort to maintain the level of particulate matter from the tobacco smoke in the auditorium to no more than 5.5 micrograms per cubic foot, filters with an effective efficiency of 90% are added to the ventilation system downstream of the point in the system where outdoor air and recirculated room air are mixed. a) What is the necessary volumetric flow rate (in cfm) for the supply outdoor air? Assume the outdoor air is clean. b) The outdoor air taken into the system becomes contaminated with tobacco smoke due to a leak in an adjacent building’s…arrow_forwardroom to be maintained with a dry-bulb temperature of 72ºF and 30% relative humidity. The room has a sensible heat factor of 0.8 and a total hourly heating load of 200,000 Btu. A flow rate of 1000 cfm of outdoor air (at 20% relative humidity and a dry-bulb temperature of 40ºF) is used. In order to maintain adequate comfort, the supply air to the room is set to a dry-bulb temperature of 120ºF. To humidify the air, steam with a specific enthalpy of 1150 Btu per pound is utilized.Determine the wet bulb temperature, specific enthalpy, and volumetric flow rate of the supply air to the room. Evaluate the increase in dry-bulb temperature as the air is sensibly heated, and the mass flow rate (in lb/hr) of steam required during the latent heating of the air. Calculate the heat added to the room during sensible heating (i.e., excluding humidification).arrow_forward
- Please can you help with the attached question? Many thanksarrow_forwardWhich of the following sequences converge and which diverge? 20) an = 21) a = n! 106 1/(Inn) 3n+1 " 22) a = 3n-1 1/n x" 23) a = , x>0 2n+1 3" x 6" 24) an 25) a, = tanh(n) = 2" xn! n² 1 26) a = sin 2n-1 n 27) a = tan(n) 1 28) a = 1 3 ++ (Inn) 200 2" 29) an n 30) =n-√√n²-n 1"1 31) a == dx nixarrow_forwardWhich of the following sequences converge and which diverge? n+1 6) a = 1- 2n (-1)+1 7) a = 2n-1 2n 8) an = n+1 1 9) a = sin + 2 n sin n 10) a = n 11) an = 12) a = 13) an 14) an 15) an 16) an n 2" In(n+1) = 81/n n n =(1+7)" = = 10n 3 n 1/n 17) an = In n 1/n n' 18) a =√4"narrow_forward
- Qu 3 Nickel (Ni) single crystal turbine blades burn less fuel at higher temperatures because blades are grown on [110] closed packed direction. Nickel (Ni) at 20°C is FCC, and has an atomic radius, R, of 0.125 nm. Draw a reduced-sphere unit cell for this crystal and draw and label the vector [I 10], starting from the origin (0, 0, 0). a) Calculate the length of the vector [| 10] in nanometers. Express your answer in nanometers to one significant figure. b) Calculate the linear density of Nickel in the [| 1 0] direction in [atom/nm]. Express your answer in atoms/nm to one significant figure. show all work problemsarrow_forwardhandwritten-solutions, please!arrow_forwardhandwritten-solutions, please!arrow_forward
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY





