A piston cylinder device contains 0.8 kg of air initially at 100 kPa, 27 °C. The air is now compressed slowly in a polytropic process during which PV^1.3 =constant, until the volume reaches 1/2 its original volume. The system is then heated at constant pressure until the volume gets back to its original value. NOTE: THIS IS NOT A CYCLE. Data: Rair = 0.287 kJ/kg K; Cv=0.731 kJ/kg K; Cp=1.018 kJ/kgK. a) Determine the amounts AND directions of the Work and Heat(each in kJ) for each of the two processes. show all work used to get your values.
I am doing some practice problems to prepare for an exam and i cannot solve this problem, specifically part a but I would like to check this problem
A piston cylinder device contains 0.8 kg of air initially at 100 kPa, 27 °C. The air is now compressed slowly in a polytropic process during which PV^1.3 =constant, until the volume reaches 1/2 its original volume. The system is then heated at constant pressure until the volume gets back to its original value. NOTE: THIS IS NOT A CYCLE.
Data: Rair = 0.287 kJ/kg K; Cv=0.731 kJ/kg K; Cp=1.018 kJ/kgK.
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a) Determine the amounts AND directions of the Work and Heat(each in kJ) for each of the two processes. show all work used to get your values.
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b) Sketch the two processes on a P-v diagram, clearly showing all three state points and the two processes with their directions.
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