A piston cylinder device shown in Figure P2.6 contains 0.1 kg of air initially at a pressure of 4 MPa and temperature of 2000 C. Heat is added to the system until the pressure is 8 MPa and the temperature is 8000 C. Sketch the process on P-V and T-V diagrams and determine the total work transfer. [Take R = 287 J/kg K]

2. A piston-cylinder assembly with stops (see figure) contains 1.54 kg of water initially occupying a volume of 1.25 m at a pressure of 1 bar (State 1). As the water in the assembly is heated, the pressure and temperature in the system remain constant until the piston contacts the stops. In this position (State 2), the quality, x2, is determined to be 92%. Heat continues to be added to the system at a constant volume until the system reaches a pressure of 1.5 bar (State 3). Determine the following quantities: а. X b. V2 (m2) C. W13 (kJ) d. Qu (kJ) e. Plot the results on a P-v diagram, labelling relevant P, T, and v values.

Please assist with part b!

A cylinder-piston apparatus contains 29 kg of air at 30°C. Weights on the piston fix the initial pressure at 20 bar. Find the work done if: a. Some of the weights are quickly removed until external pressure is 5 bar. The temperature remains constant. b. Some of the weights are slowly removed until the external pressure reaches 5 bar. The temperature remains constant. c. The expansion from 20 bar to 5 bar is polytropic, with an exponent of 1.4. Note that if the gas is ideal and PV = constant, then the temperature varies as: T₂ Tv 1-n P. n-1