A gas is contained in a vertical piston–cylinder assembly by a piston with a face area of 40 in2 and weight of 100 lbf. The atmosphere exerts a pressure of 14.7 lbf/in2 on top of the piston. A paddle wheel transfers 3 Btu of energy to the gas during a process in which the elevation of the piston increases. The change in internal energy of the gas is 2.12 Btu. The piston and cylinder are poor thermal conductors, and friction between them can be neglected. Determine the elevation increase of the piston, in ft.
