Video: Watch this demo
Description: This demo shows the buildup of charge on Styrofoam peanuts by the Van de Graff generator.
- Van de Graff machine
- Discharge wand
- Metal can with styrofoam peanuts in it
- Plastic see through bowl with styrofoam peanuts in it
- Connect the Van de Graff to a table that has a three prong cord (grounding prong); else you may get zapped when turning it off.
- Fill the metal cup and plastic bowl with styrofoam peanuts. Don’t put too many in the plastic bowl (or they won’t jump out as fast).
- With the machine off, set the machine to about half speed.
- Connect the discharge wand to the black grounding jack on the machine.
- Balance the metal can on the top of the dome and turn the machine on.
- Note that the peanuts don’t jump out because no charge enters the metal container.
- Dischage the dome and take off the metal can.
- Balance the plastic bowl on top of the dome and turn the machine on.
- Note that the peanuts jump out because charge enters the plastic container and all peanuts gain the same sign charge.
- Discharge the machine and turn it off. Remove the plastic bowl and put the peanuts back in the bowl.
Note: This works best with a small layer of peanuts (too many peanuts and they do not jump out as fast).
As with most electrostatic demonstrations, they work best under 50% humidity.