In order to determine the properties ofa dense gas at high pressures, 10 lbm of the gas was heated at 4000 psia from 700 to 740°F. The gas volumes were 0.287 and 0.328 ft^3 in the initial and final states, respectively, and the required energy transfer as heat to the gas was 537 Btu. Determine the difference in the specific internal energy between the initial and final states.