Water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer. the manometer shows a height difference of 6 inches. at the inlet of the manometer the diameter of the pipe is 1 inch and at the exit of the manometer the diameter of the pipe is 0.5 inches. assuming negligible friction, what is the flow rate (gpm) in the pipe?