2 balloons of equal size
string or thread
yard (meter) stick
tape
straight pin

Experiment Set Up

* Inflate both balloons as equally as possible.
* Find the center of gravity for the stick and tie the string around that point leaving a length of 10 inches.
* Cut two equal lengths of string.
* Tape one end of a piece of string to one end of the stick and tape the other end to a balloon.
* Repeat with the other balloon and string.
* Double-check the center of gravity on the stick.

Experiment Procedure

1. Hold stick horizontally by string tied at its center of gravity.
2. Observe and record.
3. Take the pin and carefully pop the balloon so that it does not disintegrate into small pieces. It is important to keep the balloon intact when releasing the air from it.
4. Hold stick horizontally by the string.
5. Observe and record.