Explore MyPlate with School Nutrition
September 18, 2015
Hear – See – Do Activity
Adapted from the Static Electricity with Cereal experiment, Explore MyPlate with School Nutrition booklet
“Puffed rice jump and float from a table top to a plexiglass plate.”
What you need:
- hand full of puffed rice cereal
- a square plate of plexiglass, approximately 12 in. by 12 in.
wooden blocks to balance the plate 1-3 inches above the table (table should be non-metallic)
- wool sweater
- Place the puffed rice on the table surface.
- Place the wooden blocks on the table and balance the plexiglass plate over the table and the pile of puffed rice.
- Vigorously rub the top of the plexiglass with the wool sweater.
- The puffed rice should start to stand on end, then “jump” from the table surface to the plexiglass and back again.
Explanation: The effect is caused by the buildup of static charge. Rubbing the wool sweater on the plexiglass generates a net negative charge on the plate surface. This net negative charge has the effect of polarizing the puffed rice on the table below, so positive charges accumulate on points closest to the negatively charged plate. Unlike charges attract and when the difference in charge has become great enough, the puffed rice is drawn to the bottom of the plate. When the rice contacts the plate the charges dissipate and it falls back to the table.