A piston-cylinder device contains 100 g of ethylene gas initially at 27oC, 115 kPa. Ethylene is heated and the piston starts to rise until the volume reaches 90 L and merely touches a linear spring that has a spring constant of 60 kN/m. More heat is added until the piston rises 12 cm more. Assume the atmospheric pressure to be 102 kPa.

(a) If the piston has a diameter of 18 cm, how much does this piston weigh?
(b) What is the final pressure?
(c) What is the final temperature?
(d) Determine the internal energy and enthalpy change during the process.
(e) Show the process on a P-ν diagram.
(f) Determine the work done during this process and its direction.