a)
The final temperature.
a)
Answer to Problem 216RP
The final temperature is
Explanation of Solution
Write the expression for the energy balance equation for the closed system.
Here, energy change in to the system is
Write the expression for the initial pressure in the cylinder using ideal gas law.
Here, initial pressure is
Write the expression for the mass of the air at final stage using ideal gas law.
Here, final mass is
Write the expression for the mass entering the cylinder
Conclusion:
Substitute
Here, work done during the process is
From the Table A-2” Ideal-gas specific heats of various common gases” obtain the following properties for air.
Substitute
When system undergoes constant pressure process,
Substitute
Substitute
Substitute
Thus, the final temperature is
b)
The amount of mass entered the cylinder.
b)
Answer to Problem 216RP
The amount of mass entered the cylinder is
Explanation of Solution
Substitute 315.3 K for
Substitute 1.874 kg for
Thus, the amount of mass entered the cylinder is
c)
The work done during the process.
c)
Answer to Problem 216RP
The work done during the process is
Explanation of Solution
Write the expression for the work done during the process
Here, initial volume is
Conclusion:
Substitute
Thus, the work done during the process is
d)
The entropy generated for the process.
d)
Answer to Problem 216RP
The entropy generated for the process is
Explanation of Solution
Write the expression for the entropy generated during the process.
Here, entropy generation is
Conclusion:
Substitute 1.874 kg for
Thus, the entropy generated for the process is
Want to see more full solutions like this?
Chapter 7 Solutions
Thermodynamics: An Engineering Approach
- two aluminum ingots, one weighing 1.5 kg at 450 degrees celsius while the other is 1.1 kg at 250 degrees celsius, are placed in an insulated enclosure. assuming there is no heat transfer from the ingots to the enclosure material, determine the final temperature and the entropy associated with the process.arrow_forwardRefrigerant-134a at 140 kPa and –10°C is compressed by an adiabatic 1.3-kW compressor to an exit state of 700 kPa and 60°C. Neglecting the changes in kinetic and potential energies, determine the volume flow rate of the refrigerant at the compressor inlet in L/min.arrow_forwardThe fluid is heated from 125 degrees Fahrenheit to 225 degrees Fahrenheit. Consider an ideal gas with the following characteristics: R = 85 ft-lbf/lbm-R Cp = 0.35 + 0.000325T BTU/lbm-R If the heating is at constant volume, compute for (a) the change in internal energy, (b) the change in enthalpy, and (c) the change in entropy. If the heating is at constant pressure, compute for (d) the change in entropy, and (e) the value of k at 160 degrees Celsius. If the fluid undergoes an isentropic process, determine (f) non-flow work and (g) steady-flow work. (For item f and g, use the value of k at 160 degrees Celsius). Note: The unit should be in metric system. Should have given, required and the solution.arrow_forward
- A frictionless piston-cylinder device contains a liquid-vapor mixture of water at the temperature of 400K. During an internally reversible isobaric process, 800kJ heat is transferred out from the water, and part of the vapor condenses. The entropy change of water inside the piston-cylinder is________ A. -2.0 kJ/K B. 0 C. greater than 2.0 kJ/K D. 2.0 kJ/Karrow_forwardA mass of 25 lbm of helium undergoes a process from an initial state of 50 ft3 /lbm and 60°F to a final state of 20 ft3 /lbm and 240°F. Determine the entropy change of helium during this process, assuming the process is irreversible.arrow_forwardA piston-cylinder device contains steam that undergoes a reversible thermodynamic cycle. Initially, the steam is at 400 kPa and 350°C with a volume of 0.3 m3. The steam is first expanded isothermally to 150 kPa, then compressed adiabatically to the initial pressure, and finally compressed at the constant pressure to the initial state. Indicate the processes (1-2, 2-3, and 3-1) on a P-v diagram. Determine the net work and heat transfer for the cycle after you calculate the work and heat interaction for each process.arrow_forward
- A mass of 25 lbm of helium undergoes a process from an initial state of 50 ft3 /lbm and 60°F to a final state of 20 ft3 /lbm and 240°F. Determine the entropy change of helium during this process, assuming the process is reversible.arrow_forwardRefrigerant-134a at 320 kPa and 40°C undergoes an isothermal process in a closed system until its quality is 45 percent. On a per-unit-mass basis, determine how much work and heat transfer are required.arrow_forwardA 0.05-m3 rigid tank initially contains refrigerant134a at 0.8 MPa and 100 percent quality. The tank is connected by a valve to a supply line that carries refrigerant-134a at 1.2 MPa and 40°C. Now the valve is opened, and the refrigerant is allowed to enter the tank. The valve is closed when it is observed that the tank contains saturated liquid at 1.2 MPa. Determine the mass of the refrigerant that has entered the tankarrow_forward
- A 0.06-m3 rigid tank initially contains refrigerant- 134a at 0.8 MPa and 100 percent quality. The tank is connected by a valve to a supply line that carries refrigerant- 134a at 1.2 MPa and 36°C. Now the valve is opened, and the refrigerant is allowed to enter the tank. The valve is closed when it is observed that the tank contains saturated liquid at 1.2 MPa. Determine (a) the mass of the refrigerant that has entered the tank and (b) the amount of heat transfer.arrow_forwardRefrigerant-134a at 140 kPa and 210C is compressed by an adiabatic 1.3-kW compressor to an exit state of 700 kPa and 60C. Neglecting the changes in kinetic and potential energies, determine (a) the isentropic efficiency of the compressor, (b) the volume flow rate of the refrigerant at the compressor inlet, in L/min, and (c) the maximum volume flow rate at the inlet conditions that this adiabatic 1.3-kW compressor can handle without violating the second law.arrow_forwardAir enters an adiabatic chamber steadily at 300kPa, 200 C, and 45 m/s. It leaves at 100 kPa and 180 m/s. The inlet area of the nozzle is 110cm^2. The molar mass is 29 g/mol. Determine the density of the air at the inlet of the nozzle. DeterMine the mass flow rate of air through the nozzle. Knowing the specific enthalpy of air at the inlet is 475 kJ/kg, use energy balance to determine the specific enthalpy of air at the outlet of the nozzle. Calculate the change in specific entropy between the inlet and outlet of the nozzle.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