Prob. 4-68 A piston–cylinder device contains 2.2 kg of nitrogen initially at 100 kPa and 25C....

Prob. 4-68 A piston–cylinder device contains 2.2 kg of nitrogen initially at 100 kPa and 25C. The nitrogen is now compressed slowly in a polytropic process during which PV^1.3 = constant until the volume is reduced by one-half. Determine the work done and the heat transfer for this process.

4–69 Reconsider Prob. 4–68. Using EES (or other) software,plot the process described in the problem on a P-V diagram, and investigate the effect of the poly- tropic exponent n on the boundary work and heat transfer. Let the polytropic exponent vary from 1.0 to 1.4. Plot the boundary work and the heat transfer versus the polytropic exponent, and discuss the results.

Solutions

Expert Solution

samet mamat answered 1 year ago

Next > < Previous

Related Solutions

A piston-cylinder device initially contains 0.3 m3 of nitrogen gas at 350 kPa and 35 ℃.

A piston-cylinder device initially contains 0.3 m3 of nitrogen gas at 350 kPa and 35 ℃. An electric heater within the device is turned on and is allowed to pass a 240W for 6 minutes. Nitrogen expands at constant pressure, and a heat loss of 3000 J occurs during the process. Determine the final temperature of the nitrogen. (Average CP for Nitrogen is 1.039 kJ/kgK and molecular weight of Nitrogen is 28.01 kg/kmol.)

A piston–cylinder device initially contains 2 kg water in 1 m3 at 500 kPa. The system...

A piston–cylinder device initially contains 2 kg water in 1 m3 at 500 kPa. The system then cools down and the volume drops to half and pressure of 300 kPa. At this state, the piston is resting on a set of stops, and the mass of the piston is such that a pressure of 500 kPa is required to move it. (a) Show the process on a P-v, T-v and P-T diagrams with respect to saturation lines and determine, (b)...

A piston-cylinder device, whose piston is resting on a set of stops, initially contains 2 kg...

A piston-cylinder device, whose piston is resting on a set of stops, initially contains 2 kg of air at 300 kPa and 27ºC. The mass of the piston is such that a pressure of 600 kPa is required to move it upward. Heat is now transferred to the air until its volume doubles. a) Determine the work done by the air and b) the total heat transferred to the air during this process. c) Also, sketch the process on a...

A piston-cylinder device initially contains 75 g of saturated water vapor at 310 kPa . A...

A piston-cylinder device initially contains 75 g of saturated water vapor at 310 kPa . A resistance heater is operated within the cylinder with a current of 0.4 A from a 200 Vsource until the volume doubles. At the same time a heat loss of 2 kJ occurs. a.Determine the final temperature (T2). b. Determine the duration of the process. c. What-if scenario: What is the final temperature if the piston-cylinder device initially contains saturated liquid water?

100 kg of R-134a at 320 kPa are contained in a piston-cylinder device whose volume is...

100 kg of R-134a at 320 kPa are contained in a piston-cylinder device whose volume is 7.530 m3. The piston is now moved until the volume is one-half its original size. This is done such that the pressure of the R-134a does not change. Determine the final temperature and the change in the total internal energy of the R-134a. (Round the final answers to two decimal places.)

A weighted piston-cylinder device (pressure is not constant) initially contains 1.2 kg saturated liquid water at...

A weighted piston-cylinder device (pressure is not constant) initially contains 1.2 kg saturated liquid water at 190oC. Now heat is transferred to the water until the volume quadruples (increase four times) and the cylinder contains saturated vapor only. Determine: a) The final volume of the tank. b) The final temperature and pressure. c) The internal energy change of the water.

A piston–cylinder device contains 5 kg of steam at 100°C with a quality of 50 percent....

A piston–cylinder device contains 5 kg of steam at 100°C with a quality of 50 percent. This steam undergoes two processes as follows: (1-2) Heat is transferred to the steam in a reversible manner while the temperature is held constant until the steam exists as a saturated vapor.(2-3) The steam expands in an adiabatic, reversible process until the pressure is 15 kPa. Sketch these processes with respect to the saturation lines on a single TS diagram and determine the heat...

A spring-loaded piston-cylinder device contains 0.5 kg of water initially at 90℃ and with an initial quality of 20.9%.

A spring-loaded piston-cylinder device contains 0.5 kg of water initially at 90℃ and with an initial quality of 20.9%. At its initial state, the spring is relaxed and does not exert any force on the piston. The device is now heated until the pressure is 400 kPa and the new temperature is 250℃. What is the boundary work done by the water during this process? kJ What is the total amount of heat transfer into the system? kJ BONUS: If...

The volume of 1 kg of helium in a piston-cylinder device is initially 7 m3 ....

The volume of 1 kg of helium in a piston-cylinder device is initially 7 m3 . Now helium is compressed to 3 m3 while its pressure is maintained constant at 150 kPa. Determine the initial and final temperatures of helium as well as the work required to compress it, in kJ. You may assume deal gas behavior.

A piston–cylinder device contains 0.85 kg of refrigerant-134a at -10°C. The piston that is free to...

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 10°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.

Subjects