Water flows over a triangular weir as shown in Fig. P10.80a and Video V10.7. It is propo...

Water flows over a triangular weir as shown in Fig. P10.80a and Video V10.7. It is proposed that in order to increase the flowrate, Q, for a given head, H, the triangular weir should be changed to a trapezoidal weir as shown in Fig. P10.80b. (a) Derive an equation for the flowrate as a function of the head for the trapezoidal weir. Neglect the upstream velocity head and assume the weir coefficient is 0.60, independent of H. (b) Use the equation obtained in part (a) to show that when b H the trapezoidal weir functions as if it were a rectangular weir.