1. Nitrogen at an initial state of 300 K, 130 kPa, and 0.15 m3 is compressed slowly in an isothermal process to a final pressure of 796 kPa. Determine the work done during this process and draw the P-V diagram.
2. The volume of 1 kg of helium in a piston-cylinder device is initially 3.28 m3 . Now helium is compressed to 1.765 m3 while its pressure is maintained constant at 160 kPa. Determine the initial and final temperatures of helium as well as the work required to compress it, in kJ.
3. A piston–cylinder device contains 0.124 kg of air initially at 1.698 MPa and 350 C. The air is first expanded isothermally to 330 kPa, then compressed polytropically with a polytropic exponent of 1.2 to the initial pressure, and finally compressed at the constant pressure to the initial state. Determine the boundary work for each process and the net work of the cycle.
4. An insulated piston–cylinder device contains 3.88 L of saturated liquid water at a constant pressure of 175 kPa. Water is stirred by a paddle wheel while a current of 8 A flows for 45 min through a resistor placed in the water. If one half of the liquid is evaporated during this constant-pressure process and the paddle-wheel work amounts to 290 kJ, determine the voltage of the source.
5. A rigid tank contains 10 lbm of air at 30 psia and 658F. The air is now heated until its pressure doubles. Determine (a) the volume of the tank and (b) the amount of heat transfer. Take R = 0.3704 (psia*ft3/lbmR).