Question

Complete Analysis of Heat Engine Goal Solve for the efficiency of a heat engine using a five-step process the includes: 1. Making a state table. 2. Making a process table. 3. Calculating the totals for Work, Heat, and Internal-Energy-Change. 4. Identifying the heat input (hot reservoir) and output (cold reservoir). 5. Calculating the efficiency of the engine. isothermal Problem Shown in the figure to the right is a cyclic process undergone by a heat engine. Your heat engine shall use 10.0 moles of nitrogen gas (diatomic). During the process a->b, the pressure rises by a factor of 2.0. T = 300 K Pa = 100,000 Pa Engine Cycle Solution (1) Fill in the State Table (all pressures in Pascals, all volumes in cubic meters, all temperatures in K). Pressure 100000 Volume 0.25 Temperature 300 200000 0.25 601.4 100000 0.5 601.4 Work Heat 62640 du 62640 (2) Fill in the Process Table (all entries in Joules). * * * * * 34660 34660 -25000 -87700 c- >a -52700 , (3) Find the Totals: Work = 9660 Heat = 9600 dU = 9940

Answer 1

Sol" :- Given - A three process cycle, arb, b-c, c-a Also, we have, N T =const Ta = 300k Pa = 100,000 Pa Pa = 100 kPa According to question, (P = 2 Pa) Ne gas with number of mole, na lo moles TPV=nRTs valid Cvs 20.783 J/mole-k Cpa 29.096 $/molek Now (2) change in internal eringy for ca procees, As we know the internal energy is point functions and also its change in a cyclic process is equal to zero For this cycle, du + dus + du to SO 62640 + 0 + 0 =0 de =-62 640 j) са

(3) Totals, we know the cyclic change in interne energy is equal to zero. ii (dul = 62640 -62640 Total o we have From (3), Ew=Wnet. = 9660 Qin - Qout = Woes. [Hot] Gun - Quot - Qold = Wired. ii Quid =97300 - 9660 Pald - 87640 5] [cold out *Qout