2-Liter pop bottle filled with water, marbles, cork
2-Liter pop bottle filled with water, marbles, cork on a rotating air table

 

Code Number: 1D52.30

Demo Title: Water Centrifuge with Cork and Balls

Condition: Excellent

Principle: Central Forces

Area of Study: Mechanics, Fluid Dynamics

Equipment:

 2-Liter pop bottle, steel balls, marbles, cork.

Procedure:

Place the steel balls or marbles and a cork  in a 2-Liter pop bottle and fill with water.  Place the bottle on its side in the middle of the rotating air table and give it a spin.  The cork should move to the center of the bottle while the marbles or steel balls should move to the ends of the bottle.

References:

  • Keith Bellof, "Student-Discovered Gem", TPT, Vol. 45, # 8, Nov. 2007, p. 524.
  • Martin Gardner, "The Marble and the Cork", TPT, Vol. 34, # 3, p. 146, March 1996. 
  • Thomas J. Pickett, "The Marble, Cork, and Centrifuge", TPT, Vol. 34, # 7, p. 422, Oct. 1996.
  • Martin Gardner, "The Marble and the Cork", p. 15.
  • Neil. A. Downie, "Centripetal Chaos", Ink Sandwiches, Electric Worms and 37 Other Experiments for Saturday Science, p. 134.
  • Borislaw Bilash II, “Measuring Acceleration“, A Demo A Day – A Year of Physical Science Demonstrations, p. 221.