2C20.48 - Coanda Effect - Magnetic Ping - Pong Ball

Code Number:
2C20.48
Demo Title:
Coanda Effect - Magnetic Ping - Pong Ball
Condition:
Good
Principle:
Bernoulli's Principle
Area of Study:
Heat & Fluids
Equipment:
Large Diameter Laminar Water Stream, and Ping-Pong Ball on a String.
Procedure:

Just as a ping-pong ball will be stable in an upward directed water stream, so will it be in a downward directed stream. Adjust the flow until you get a smooth steam. Put a string on a ping-pong ball and hold the string about 8 to 12 inches from the ball. Put the ball into the water stream and you can feel the stream "pulling" in the ball. You should be able to pull on the string at a large angle from the vertical before the ball can be pulled out of the stream.

References:
  • T. López‐Arias, L. M. Gratton, S. Bon, and S. Oss, "'Back of the Spoon' Outlook of Coanda Effect", TPT, Vol. 47, #8, Nov. 2009, p. 508.
  • Robert Ehrlich, "H.10. Ping-Pong Ball Near a Water Stream, Turning the World Inside Out and 174 Other Simple Physics Demonstrations, p. 105.
  • Martin Gardner, "14. A Table Tennis Ball Experiment", Smart Science Tricks, p. 27.
  • Joey Green, "Magnetic Ping-Pong Ball", The Mad Scientist Handbook, Vol. 2, p. 61.




Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.