Quickly Dropping Light Objects

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What type of experiment is this?

Experimental procedure and explanation:

• When an object is dropped in air, air　resistance works on that object. Air resistance is primarily caused by the “separation” that occurs behind the object and the viscous friction of the air. Separation is a vortex that is formed behind an object and is a factor that works to significantly increase air resistance.
• The speed at which an object falls varies depending on the magnitude of the gravitational force and of air resistance. As the gravitational force is increased (or as the weight of the object increases), the object will fall faster. Conversely, air resistance acts as a brake and works to reduce the speed at which the object drops.
• The bag and tissue paper are lightweight (the gravitational force is small), and fall very slowly due to the effect of air resistance.
• However, when the bag and tissue paper are placed on the top of a magazine, separation occurs behind the magazine and a circulating flow is formed. This flow causes the bag and tissue paper to stick to the magazine. As a result, the bag and tissue paper drop at approximately the same speed as the magazine.

[Keywords]	separation, air resistance
[Related items]	Heavy Ball and Light Ball, Candle Behind a Flat Plate, Air Flow Behind a Board
[Reference]	The Japan Society of Mechanical Engineers, “The Wonders of Flow (Nagare no Fushigi),” Kodansha Blue Backs, pp. 136–139. Ryozo Ishiwata, “Illustrated Fluid Dynamics Trivia (Zukai Zatsugaku Ryutai Rikigaku),” Natsume Publishing, pp. 66–69.