Hydrogen is contained in a piston-cylinder device at 14.7 psia and 15 ft 3. At this state, a linear spring ( ) with a spring constant of 15,000 lbf/ft is touching the piston but exerts no force on it. The atmospheric pressure acting on the piston is 14.7 psia. The cross-sectional area of the piston is 3 ft2. Heat is transferred to the hydrogen, causing it to expand until its volume doubles. Determine (a) the final pressure [psia], (b) the total work done by the hydrogen [ft-lbf], and (c) the fraction of this work done against the spring [%].