At a hydraulic jump, the flow depths are 0.4 m and 5 m at the upstream and downstream, respectively. The channel is wide rectangular. The discharge per unit width is nearly

Concept:

Hydraulic Jump: It is a phenomena associated with sudden rise in water depth when a flow with high velocity and low depth (supercritical flow) strikes another flow with low velocity and high depth (subcritical flow).

For any hydraulic jump, the following relation always holds good:

Where, y₁ and y₂ are the depths before and after the hydraulic jump respectively.

q is discharge per unit width and g is acceleration due to gravity.

Calculation:

Given, upstream depth which is depth before hydraulic jump = y₁ = 0.4 m.

Downstream depth which is depth after hydraulic jump = y₂ = 5 m.

Acceleration due to gravity = g = 9.81 m/s².

∴ The discharge per unit width is nearly 7.3 m²/s.