Changes

[[File:Hydraulicjump.jpg|200px|thumb|left|A hydraulic jump in the river]]

[[File:Hydraulicjump.jpg|300px|thumb|left|A hydraulic jump in the river]]

A hydraulic jump is a discrepancy in water levels. When water in a stream flows over a rock, the water may reach supercritical speed - that is, the speed of the water may exceed the speed that waves propagate at. If so, there will be a sudden change in the water's height so that the speed of the water is reduced to subcritical speed.

A hydraulic jump is a discrepancy in water depths. When water in a stream flows over a rock, the water may reach supercritical speed - that is, the speed of the water may exceed the speed that waves propagate at. If so, there will be a sudden change in the water's height so that the speed of the water is reduced to subcritical speed.

The equation that governs this phenomena is:

The equation that governs this phenomena is:

<math>H_2/H_1 = 1/2(<sqrt>8(F_1)^2 + 1</sqrt> - 1)</math>

<math>\frac{H_2}{H_1} = \frac{1}{2}(\sqrt{8{F_1^2} + 1} - 1)</math>

where <math>F_1 = <sqrt>gY_1</sqrt></math>

where <math>F_1 = \sqrt{g}{Y_1}</sqrt></math>

F_1 is called the Froude number, g is the acceleration due to gravity, and Y_1 is the depth of the water.

F_1 is called the Froude number, g is the acceleration due to gravity, and Y_1 is the depth of the water.