Required information A piston-cylinder device contains 0.82 kg of refrigerant-134a at -10°C. The piston that is free to move has a mass of 12 kg and a diameter of 25 cm. The local atmospheric pressure is 88 kPa. Now, heat is transferred to refrigerant-134a until the temperature is 15°C. Use data from the tables. R-134a -10°C Determine the change in the enthalpy of the refrigerant-134a. The change in the enthalpy is 21.3 kJ.

Required information A piston-cylinder device contains 0.82 kg of refrigerant-134a at -10°C. The piston that is free to move has a mass of 12 kg and a diameter of 25 cm. The local atmospheric pressure is 88 kPa. Now, heat is transferred to refrigerant-134a until the temperature is 15°C. Use data from the tables. R-134a -10°C Determine the change in the enthalpy of the refrigerant-134a. The change in the enthalpy is 21.3 kJ.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

A 0.8-m3 rigid tank contains carbon dioxide (CO2) gas at 250 K and 100 kPa. A 500-W electric resistance heater placed in the tank is now turned on and kept on for 40 min, after which the pressure of CO2 is measured to be 175 kPa. Assuming the surroundings to be at 300 K and using constant specific heats, determine the final temperature of CO2.
A 0.8-m3 rigid tank contains carbon dioxide (CO2) gas at 250 K and 100 kPa. A 500-W electric resistance heater placed in the tank is now turned on and kept on for 40 min, after which the pressure of CO2 is measured to be 175 kPa. Assuming the surroundings to be at 300 K and using constant specific heats, determine the net amount of heat transfer from the tank.
Q9/ A piston-cylinder device contains 0.85 kg of refrigerant- 134a at 10°C. The piston that is free to move has a mass of 12 kg and a diameter of 25 cm. The local atmospheric pressure is 88 kPa. Now, heat is transferred to refrigerant-134a until the temperature is 15°C. Determine (a) the final pressure, (b) the change in the volume of the cylinder, and (e) the change in the enthalpy of the refrigerant-134a.
A 0.68 m3 rigid tank contains refrigerant-134a initially at 100 kPa and 40 percent quality. Heat is now transferred to the refrigerant until the pressure reaches 400 kPa. Determine Final temperature the mass of the refrigerant in the tank the amount of heat transferred.
A 2-ft3 rigid tank contains saturated refrigerant- 134a at 160 psia. Initially, 5 percent of the volume is occupied by liquid and the rest by vapor. A valve at the top of the tank is now opened, and vapor is allowed to escape slowly from the tank. Heat is transferred to the refrigerant such that the pressure inside the tank remains constant. The valve is closed when the last drop of liquid in the tank is vaporized. Determine the total heat transfer for this process.
A piston–cylinder device contains 0.85 kg of refrigerant134a at –10°C. The piston that is free to move has a mass of 12 kg and a diameter of 25 cm. The local atmospheric pressure is 88 kPa. Now, heat is transferred to refrigerant-134a until the temperature is 15°C. Determine (a) the final pressure, (b) the change in the volume of the cylinder, and (c) the change in the enthalpy of the refrigerant-134a.
An insulated 40-ft3 rigid tank contains air at 50 psia and 120°F. A valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. The air temperature during this process is kept constant by an electric resistance heater placed in the tank. Determine the elec- trical work done during this process.
Is the energy required to heat air from 295 to 305 K the same as the energy required to heat it from 655 to 675 K? Assume the pressure remains constant in both cases. Explain??
THERMOFLUID A rigid vessel contains 8 kg of refrigerant-134a at 500 kPa and 120°C. Determine the volume of the vessel and the total internal energy.
At t = 280 degrees celcius and S = 5.72 Kj/kg-K. Determine the Enthalpy and Internal Energy with the use of steam tables.
A liquid R-134a bottle has an internal volume of 0.001 m3 . initially it contains 0.4 kg of R-134a (saturated mix) at 26oC. A valve is opened and R-134a vapor only is allowed to escape slowly such that temperature remains constant until the mass of R-134a remaining is 0.1kg. find heat tranfer necessary with the surroundings to maintain the temperature and pressure of R-134a constant.
A student living in a 4 - m 5 - m 3 - m dormitory room turns on her 100 - W fan before she leaves the room on a summer day, hoping that the room will be cooler when she comes back in the evening. Assuming all the windows are tightly closed and disregarding any heat transfer through the walls and the windows, determine the temperature in the room when she comes back 8 h later. Use specific heat values at room temperature, and assume the room to be at 100 kPa and 20 ° C in the morning when she leaves.