I found one project so far where you can change the density of water to make an egg sink, float, or stay submerged. I want something similar but not exactly the same.
2007-02-22 12:46:43 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
Okay, get a very large, sealable jar with a valve at top, connected to a hand operated air pump. Fill most of the jar with water, but not all of it. In the water, put in a small balloon filled with a liquid heavier than water, but also add just a bit of air in it, so that it has a small air bubble. Adjust the size of the air bubble so that normally the balloon will just float to the surface of the water. If you pump air into the air, you can control the buoyancy of the balloon in the water, so that it can sink, and even reach the bottom. Letting air out of the jar will restore its buoyancy.
Theory: The air in the balloon is compressed to the same pressure as the air in the jar. Thus, you can cause the air bubble to shrink, and thereby make the balloon "denser", and change its buoyant properties.
You might even want to try this surreptitiously, so that the audience does not know that there's an air tube connected to the jar, and you are pumping air with a secret remote device. But then again, that would be for a magic show, right?
Hazard advice: I recommend using a plastic jar, or better yet, a plastic tube, as it is possible to shatter a big glass jar with this experiment, if not done right. It does not take much air pressure to shatter a very large glass jar.
2007-02-22 13:07:42 · answer #1 · answered by Scythian1950 7 · 0⤊ 0⤋
Totally Lava lamps.
Hard to make, but pretty cool & very demonstrative of density & buoancy.
We made them with water & b....something...alcohol, but mineral oir & wax works too. The trick is, the densities have to be close enough so the hot wax (alcohol) floats, and the cold sinks.
It's pretty tricky actually.
2007-02-22 13:37:05 · answer #2 · answered by D E W 1 · 0⤊ 0⤋
lava lamps.
as the wax heats up it rises, when it cools down it sinks back down.
a galileo thermometer uses a similar principle to tell you the temperature.
either of those is a cool project or at elast a demonstration of buoyancy.
2007-02-22 12:53:49 · answer #3 · answered by Tim C 5 · 0⤊ 0⤋
Use a boat for a little dramatic effect.
2007-02-22 14:09:45 · answer #4 · answered by John 4 · 0⤊ 0⤋