Q1: If the head over the triangular notch is doubled, the discharge will increase by __________ times.

ANS:C - 5.657

The discharge QQQ over a triangular notch is proportional to the square root of the head HHH over the notch. According to the principles governing triangular notch flow: Q∝HQ \propto \sqrt{H}Q∝H​ Therefore, if the head HHH is doubled, the discharge QQQ will increase by: QnewQold=2HH=2\frac{Q_{\text{new}}}{Q_{\text{old}}} = \frac{\sqrt{2H}}{\sqrt{H}} = \sqrt{2}Qold​Qnew​​=H​2H​​=2​ Calculating the value of 2\sqrt{2}2​: 2≈1.414\sqrt{2} \approx 1.4142​≈1.414 Therefore, if the head over the triangular notch is doubled, the discharge will increase by approximately 1.414\boxed{1.414}1.414​ times.