Water at 20 c flows from one large reservoir to another via a 60 cm id cast iron piping system when a ball valve near the end of the pipes is completely open. the goal is to have a minimum volumetric flow rate of 10 m3/s at all times. assume the pipe inlet and exit are well- rounded; the piping system consists of 120 total meters of pipe, six threaded 90 smooth-bend elbows, and two 45° threaded elbows. what elevation in the higher reservoir must be maintained to meet the minimum flow rate requirement?