Remove the disk from the tube

Let's take a look!

What type of experiment is this?

Experimental procedure and explanation:

• Remove the polystyrene foam disk from the tube with the wind from a hair dryer. The experiment used seven disks with diameters of 10 cm and thicknesses of 2 cm. The tube diameter (inner diameter) is 11.4 cm, and the depth is 30 cm.
• Blow the wind along the wall of the tube to lift the disk. The principle is the same as "Removing a Ball from a Cylinder". There is a large pressure at the point where the air flow turns back, and at the bottom of the tube, it is approximately the same pressure. The disk rises when the force that pushes up the underside of the disk increases. When the disk rises, blow air into the tube and take out the disk.
• In this experiment, air was flowed along the wall, but there is also a method of letting air flow out by aiming at the center of the disk (Remove a ball or egg from the tube).

[Keywords]	Momentum theory, pressure
[Related items]	Removing a Ball from a Cylinder, Remove a cone from the tube, Remove a ball or egg from the tube
[Reference]	“Illustrated Fluid Dynamics Trivia,” by Ryozo Ishiwata, Natsume Publishing, P200-201

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