I recently watched a video of Veritasium where balls are juggled in water jet. I was personally so impressed that I wanted to share with u all. Its like noting you have seen before, its an invention that seems out right magical.
First of all ,we may get it confused with Bernoulli effect. But the mechanism is not the Bernoulli effect… Its something different called “Hydrodynamic Levitation” which provide these balls ablility to levitate on an upward stream of water. Hydrodynamic Levitation is a physical property which provides the ability to levitate a lightweight ball or disc atop a jet of water. The trick involves getting the water to flow along one side, runs up and over the object, creating a state of equilibrium which allows it to spin.
Light balls, disks, and cylinders will levitate on a stream of water in a surprisingly off-center way.
The standard Bernoulli effect relies on the object being completely immersed in the upward-flowing fluid. Here, the water seems to form a single stream around the object and it’s deflected away and down from the stream. By Newton’s third law, the force on the water by the ball is equal and opposite to the force of the water back on the ball, pushing it up into the stream. There is a stable equilibrium position because if the ball moves into the stream, it “cuts off” the water going over the ball so it drifts out. If it drifts out too far, then lots of water passes over the ball, pushing it back into the stream.
Watch the video, try it yourself at home and get mesmerised…