2C60.10 - Fluidizing Bed

Code Number:
Demo Title:
Fluidizing Bed
Area of Study:
Large Plastic Container with Sand Blasting Beads, Balls of Different Densities, Compressed Air, and Toy Boat.

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.

Video Credit: Daniel Reinart.

  • 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.

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