1. Overnight a thin layer of ice forms on the surface of a river. Estimate the percent reduction in flowrate caused by this condition. List all assumptions and show all calculations.
2. The cross section of a long tunnel carrying water through a mountain is as indicated in Fig. P10.58. Plot a graph of flowrate as a function of water depth, y, for 0 ≤ y ≤ 18 ft. The slope is 2 ft/mi and the surface of the tunnel is rough rock (equivalent to rubble masonry). At what depth is the flowrate maximum? Explain.
