Question

The head of water over a rectangular notch is 900 mm. The discharge is 300 litres/s. Find the length of the notch, when CD =.62

(a) .192 m

(b) .250 m

(c) .205 m

(d) .175 m

This question was posed to me by my school principal while I was bunking the class.

I'm obligated to ask this question of Discharge over a Rectangular, Triangular, Trapezoidal & Stepped Notch topic in chapter Orifices, Mouthpieces, Notches and Weirs of Fluid Mechanics

Answer 1

The correct choice is (a) .192 m

To elaborate: L = 1.5 * Q / (Cd * √2g * H ^ 1.5)

                      = 1.5 * .3 / (.62 * √19.62 * .9^1.5)

                      = .192 m.