Question

0.01 kg of Air at 300 K and 100 kPa (state 1) is compressed in a piston cylinder (closed system). The compression process is

Need help with 2.3, my lecturers answers say that the efficiency is 55.9% and the T2s is 439.3K. If this is incorrect please elaborate on why, if it is correct please show working. Thank you!

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Given mass, m = 0.01 kg State 1 Pa = 100 kPa T1 = 300 K State 2 P2 = 380 kPa T2 = 360K (2.1) From ideal gas equation Pin er S

1n) = n in C) Or Substituting the known values in (100 n = 1.158 (2.2) Polytrophic work done is given by . W = P2V2 - PV 1-n

380 (1.4-1)/1.4 Tas = 300 (100) = 439.3K Work done on the system during the process W = mcp(Tas – Ti) = 0.01 > 1.005 % (439.3

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