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Code Number: 2C60.10
Demo Title: Fluidizing Bed
Condition: Excellent
Principle: Fluidization
Area of Study: Fluids
Equipment:
Large Plastic Container with Sand Blasting Beads, Balls of Different Densities, Compressed Air, and Toy Boat.
Procedure:
Connect the air hose to the compressed air and the connection on the plastic container. Turn on just enough air to see some geysers appear in the beads. A buried ping pong ball will rise when the air is turned on, and a steel ball bearing will sink. A golf ball is almost neutrally buoyant and will sink half way into the beads but still be visible. A toy boat will be able to "sail" in the beads just as it can in the water.
References:
- Eric Bertin, "Statistical Physics of Frictional Grains: Some Simple Applications of the Edwards Statistics", AJP, Vol. 92, #5, May 2024, p. 375.
- D. A. May and J. J. Monaghan, "Can a Single Bubble Sink a Ship?", AJP, Vol. 71, #9, Sept. 2003, p. 842.
- Bruce Denardo, Leonard Pringle, Carl DeGrace, and Michael McGuire, "When Do Bubbles Cause a Floating Body to Sink?", AJP, Vol. 69, #10, Oct. 2001, p. 1064.
- George Spagna, "Buoyant Force Analog: A Demonstration for the Vertical Stage Overhead Projector", AJP, Vol. 49, #5, May 1981, p. 507.
- Alex Lopatka, "Flows of Volcanic Rock and Gas Ride a Carpet of Air", Physics Today, Vol. 72, #6, June 2019, p. 19.
Video Credit: Daniel Reinart.