Cartesian+Diver

Hey Jason,

This is a good start setting up this page, but how about something on it. Let's start by you posting some simple ideas about density and buoyancy.

The Cartesian Diver works because of two concepts, density and buoyancy. Density is the amount of mass per unit per volume of material. Buoyancy is the force that causes objects to float. According to the principle of Archimedes, when a solid is placed in a fluid (a liquid or a gas), it is subject to an upward force equal in magnitude to the weight of the fluid it has displaced. The straw, or the top of the diver, traps a tiny amount of air. Because of the air in the top of the diver, the density of the diver becomes very little and the diver floats.

When you squeeze the bottle, the air trapped in the straw condenses because the molecules in the air are farther apart and are easer to compact than the water. Therefore the straw has less volume but still has the same mass. When that happens the diver gets more dense, and because it was barely floating before, it sinks to the bottom. For example even though a boat is very heavy, it floats beacause it has the force of the weight of the water it displaces pushing upward on it.

Drawing made by Jason Hunyar The file size for this video was to big so I had to create a photobucket (that I am never going to use again). Here is the link to the video. []

The formula to find density is D (density)= __M (mass)__ V (volume)

For example if the weight of an orange was 500 grams and the volume (the amount of water it displaces) was 1.5 liters, the density would be 1/3 and the orange would float.