Question

Problem 6.028 SI Air contained in a rigid, insulated tank fitted with a paddle wheel, initially at 300 K, 2 bar, and a volume of 2 m, is stirred until its temperature is 600 K. Assuming the ideal gas model for the air, and ignoring kinetic and potential energy, determine (a) the final pressure, in bar (b) the work, in kJ (c) the amount of entropy produced, kJ/K Solve using: (1) data from Table A-22. (2) constant cy read from Table A-20 at 400 K.

Answer 1

P:9 bar = 2x165 N/m2 T, 300k V, m Ta 60ok Soution insulated o Tonk Valume Constont Laken Values Feam tabla Jovaing ain Far R: 287 K KJ KAK C 0.718 P.V. mRT P.V. kg s 4.645 RT x 300 281 PL C 2X105 Ps Go0 300 4 X105 N/m Final Preue Pa The wask Q=W+ Du Au - W

So w Work negative on tae 8ystem CT-T) (600-300 4.645 X 718 x W lo00.5 K J Amount entrops Prooluce d dls Mcy in (4) 4-645 x 0718 ds = 2.31 Result a Final pressura 4X10 NIm 4 bar W 00o.5 KS Wook entropy produd ds 9.31 KJ