Question

The sequent depth ratio of a hydraulic jump in a rectangular horizontal channel is 10.30. The Froude Number at the beginning of the jump is

• A. 5.64
• B. 8.05
• C. 7.63
• D. 13.61

Answer 1

The correct option is C 7.63

$\frac{y_2}{y_1}=\frac{1}{2}[-1+\sqrt{1+8F_{r_1}^2}]$

$\Rightarrow 10.3=\frac{1}{2}[-1+\sqrt{1+8F_{r_1}^2}]$

$\Rightarrow 20.6=-1+\sqrt{1+8F_{r_1}^2}$

$\Rightarrow (21.6{)}^2=1+8F_{r_1}^2$

Solving the above equation, we get

$F_{r_1}=7.63$