A rigid well insulated tank of volume 3.2ft^3 contains air at P1 = 18lbf/in2 and T1 = 480 oR. The air is stirred by a paddle wheel, resulting in an energy transfer to the gas of magnitude 4750ft-lbf. Assuming ideal gas behavior for the air and neglecting kinetic and potential energy effects, determine the
a) Mass of the air lbm
b) Final temperature in *R?
c) Final pressure in psi?