Project 2.2 Make a Cartesian Diver

Soda Bottle Physics: The Cartesian Diver
A very simple Cartesian diver can be made using a 2-liter soda bottle and a condiment packet. Place the condiment packet in the bottle and fill the bottle completely with water.

If the packet sinks in the water, select a different packet.

The volume of air inside the packet can be changed by squeezing the bottle. As the volume decreases, it loses buoyancy and sinks. when the pressure is released, its volume should increases again and float to the top.

An eye-dropper partially filled with water also works well. You will need to experiment with the initial volume of air in the dropper.