Question

A certain gas of mass 4 kg is contained within a piston cylinder assembly. The gas undergoes a process for which PV1.5 =constant. The initial state is given by 3 bar, 0.1 m3. The decrease in internal energy of system is 4.6kJ/kg. Find the net heat transfer for the process when the final volume is 0.2 m3. Neglect the changes in KE and PE​

Answer 1

Answer:

Four kilograms of a certain gas is contained within a piston-cylinder assembly. The gas undergoes a process for which the pressure-volume relationship is: V1.5 = constant The initial pressure is 3 bar, the initial volume is 0.1m3, and the final volume is 0.2m3. The change in the specific internal energy of the gas in the process is u2-u4.6kJ/kg. Determine the net heat transfer for the process u2-ui =-4.6 kJ/kg pV1.5 constant as pW.5= constant Area = work

Answer 2

Answer:

-0.8 kJ

Explanation:

P2 = P1 (V1/V2)^1.5 = 3 x 10^5 (0.1/0.2)^1.5 = 1.06 x 10^5 Pa

W12 = (P1V1-P2V2)/n-1 = ((3 x 10^5)(0.1) - (1.06 x 10^5))/ (1.5 -1) = 17.6 kJ

Q = m∆u + W12 = 4 x (-4.6) + 17.6 = -0.8 kJ