Water at 70°F flows by gravity from a large reservoir at a high elevation to a smaller one through a 58-ft-long, 2-in-diameter cast iron piping system that includes four standard flanged elbows, a well-rounded entrance, a sharp-edged exit, and a fully open gate valve. Taking the free surface of the lower reservoir as the reference level, determine the elevation 21 of the higher reservoir for a flow rate of 10 ft3/min. The density and dynamic viscosity of water at 70°F are p= 62.30 lbm/ft3 and u = 2.360 lbm/ft-h = 6.556 x 10-4 lbm/ft:s. The roughness of the cast iron pipe is ε = 0.00085 ft. = The elevation 21 of the higher reservoir is 11.81 ft.