Oxygen flows without a gain or loss of heat through a horizontal pipe of constant cross section. At section 1 the pressure 175 psia, the velocity is 78 fps, and the temperature is 50°F; at section 2 the pressure is 130 psia, the velocity is 95 fps, and the temperature is 30°F. Between sections 1 and 2, find:
a. The head (mechanical energy) loss in BTU/lb
b. The change in enthalpy