Figure P10.113 shows a channel contraction section often called a venturi flume [from Ref. 23 of Chap. 10], because measurements of y1 and y2 can be used to meter the flow rate. Show that if losses are neglected and the flow is one-dimensional and sub-critical, the flow rate is given by Apply this to the special case b1 = 3 m, b2 = 2 m, and y1 = 1.9 m. Find the flow rate
(a) If y2 = 1.5 m; and
(b) Find the depth y2 for which the flow becomes critical in the throat.

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