Make a Vibrating Balloon Toy
In this science experiment, kids use a hex nut placed inside an inflated balloon to explore forces and sound vibrations.
This simple project demonstrates several physics principles:
- As you spin the balloon, the centrifugal force causes the hex nut to spin around and around the outside edges of the balloon. This is the opposite of a centripetal force, which draws things to the center.
- The hex nut will continue to spin inside the balloon even after you stop spinning the balloon itself. This is because of inertia -- an object in motion will stay in motion until another force acts on it. In this case, the hex nut will continue to spin until friction with the wall of the balloon slows it down.
- The screaming sound comes from the vibrations made when the bumps in the hex nut bang against the wall of the balloon.
Extension: Try using a penny instead of a hex nut. The penny will flip up onto its side and spin around the inside of the balloon. There will be no screaming, however, because the penny does not have bumpy edges like the hex nut.
Safety Notes
Only adults should blow up the balloon with the hex nut inside. The hex nut could fall out of the balloon, creating a choking hazard.
Materials
- Balloon (transparent is best) - 1 of this item per student
- 1/4" hex nut - 1 of this item per student
Instructions
Place the hex nut inside the balloon. A transparent balloon works best because you will be able to see the hex nut spinning around inside.
ADULTS ONLY: inflate the balloon and tie the end.
Hold the balloon with the tied end in one hand and the top of the balloon in the other. Gently begin rotating the balloon until the hex nut is spinning around inside. What makes the hex nut spin around the balloon in a circle? What is that sound?
