PURPOSE: To show coulomb repulsion.
DESCRIPTION: Mylar balloons are filled with helium and secured to a table. When the charged dome of the Van de Graaf generator is brought into contact the balloons become charged and repel.
Some variations on this theme are to tape the two balloons to the top of the Vand de Graaf dome with some conductive thread. The conductive thread can be made by dipping the fingers into salt water and running your fingers along the length of some cotton thread. Also, pie pans or rice crispies can be placed onto the top of the Van de Graaf dome.
EQUIPMENT: The Mylar balloons and the Van de Graaf are stored in the electricity and magnetism cabinet. The gaseous helium is stored on the second floor.
SETUP TIME: It takes fifteen minutes to run up to the second floor and inflate the balloons.
Updated by Jun Qi in 3/9/2000