- Floating Without Water
This week's experiment is very simple, but surprisingly fun. We are
used to seeing things float in liquid, but we don't think of something
floating in a solid.
For this experiment, you will need:
* a clear jar or some other clear container with a
top that can be sealed
* uncooked rice
* a cork or pingpong ball
Fill the jar about 1/3 full of rice. Place the cork into the jar and
seal the top. Now, turn the jar upside down. The cork should be buried
under the rice. Now, start tapping the side of the jar and you will see
the cork rise through the rice to the top.
Why does this happen? It happens for the same reason that a cork floats
in water. The rice is heavier than the cork. As you shake the jar, the
heavier rice sinks to the bottom and lifts the lighter cork to the top.
As I said, it really is a simple experiment, but it has a lot of
potential. Try using different objects. If they are heavier than the
rice, they will go to the bottom. If they are lighter, they will rise.
Try other things besides rice. Sand, salt, and sugar would be fun. Try
putting objects of different densities into the rice, to see if some
rise faster than others. As with many of the simple experiments, the
more I played with this one, the more fun I had with it.