The volume of 1 kg of helium in a piston–cylinder device is initially 5 m3. Now helium is compressed to 3 m3 while its pressure is maintained constant at 130 kPa. Determine the initial and final temperatures of helium as well as the work required to compress it, in kJ. The gas constant of helium is R = 2.0769 kJ/kg·K.   The initial temperature of helium is  K. The final temperature of helium is  K. The work required to compress helium is  kJ.

A piston-cylinder device initially contains 0.4 kg of nitrogen gas at 160 kPa and 140°C. Nitrogen is now expanded isothermally to a pressure of 80 kPa. Determine the boundary work done during this process. The properties of nitrogen are R= 0.2968 kJ/kg-K and k= 1.4. N₂ 160 kPa 140°C The boundary work done during this process is KJ.

! Required information An abrasive cutoff wheel has a diameter of 5 in, is 1/16 in thick, and has a 3/4-in bore. The wheel weighs 4.80 oz and runs at 11,700 rev/min. The wheel material is isotropic, with a Poisson's ratio of 0.20, and has an ultimate strength of 12 kpsi. Choose the correct equation from the following options: Multiple Choice о σmax= (314) (4r2 — r²) - о σmax = p² (3+) (4r² + r²) 16 σmax = (314) (4r² + r²) σmax = (314) (4² - r²)