Water flows downward in a pipe at 45*, as shown in Fig. P2.44. The pressure drop p1-p2 may be due to flow friction, elevation change, or both. The mercury manometer reads a 6-in height difference. What is the total pressure drop p1-p2 in lbf/in^2? What is the pressure drop due to friction only between 1 and 2 lbf/in^2? Does the monometer reading correspond only to friction drop? Why?