Two uninsulated, rigid tanks contain air. Initially, tank A holds 1 lbm of air at 1440°R, and tank B has 2 lbm of air at 900°R. The initial pressure in each tank is 50 psi. A valve in the line connecting the two tanks is opened and the contents are allowed to mix. Eventually, the contents of the tanks come to equilibrium at the temperature of the surroundings, 520°R. Determine the amount of energy transfer by heat, in Btu, and the final pressure, in psi.