If you have ever played with water balloons, you know how easily they break. I accidentally came across this one while playing with....I mean experimenting with some water balloons. After filling a balloon halfway with water, I decided to inflate it the rest of the way with air. The results were very interesting.
For this experiment, you will need:
- several balloons - 7 inch or larger balloons work very well
- a faucet to fill the water balloons
- an area where you can make a mess with water
Start by filling a balloon with water. Tie it off, and then find a nice, hard surface where it is OK to make a mess. Hold the water balloon about shoulder high and drop it. It will probably break when it hits the ground.
Next, fill a balloon half full of water and then (holding the neck of the balloon to avoid making a bigger mess) inflate the balloon the rest of the way with air. If you are not careful, you will get a face full of water, but that is half the fun. Now, tie off the half and half balloon. Hold it at arm's length and drop it. Unless you drop it on something sharp, it will not pop, even though it is falling just as fast as the one that was filled with water. (Remember that, ignoring air resistance, gravity causes different objects to fall at the same rate, regardless of weight.)
What is different about a full water balloon and a half and half balloon? Obviously, the air, but why would that make such a difference? Air is compressible, while water is not. When you drop the half and half balloon, the air inside is compressed, absorbing part of the shock. This lessens the stress on the balloon and keeps it from popping as easily. Play with this half and half balloon and you will see that it can take quite a bit of impact and still not pop, unless you accidentally throw it at your little brother, but of course, I would never do that.
Have a wonder-filled week.
