Hydrogen gas is contained in a vertical piston-cylinder device at 14.7 psia and 15 ft3. At this state, a linear spring with a spring constant of 12,000 lbf/ft touches the top of the piston but exerts no force on it. The cross-sectional area of the piston is 2.5 ft2. Heat transfer occurs to hydrogen gas, pushing the piston upwards against the spring, and the hydrogen gas expands until its volume doubles.
(a) Show the process on a p-V diagram.
(b) Determine final pressure (psia) of the hydrogen gas.
(c) What is the total work done (Btu) during the expansion process?
(d) What fraction of the above work (Btu) is done against the spring?