Paul J. Dolan, Jr., Dept. of Physics & Astronomy, University of Maine, Orono *

A recent article in "The Physics Teacher"(1) discusses the fact that an object floating on water, by buoyancy, will be attracted when approached by a charged rod, whereas an object floating primarily by surface tension will be repelled when approached by the same charged rod. The effect is stronger than the article suggests, and can be seen with many different materials. The repulsion effect will be demonstrated, as well as a method of demonstrating the mechanism that causes the repulsion.

*Permanent address: Physics Department, Northeastern Illinois University, Chicago.

1.) "Tokar’s Question", The Physics Teacher 38, 488 (November 2000).