2B40.30 Cartesian Divers
Concepts
Buoyancy
Overview
A Cartesian diver is an object with a compressible air bladder to change its density. When the diver is placed in a sealed water bottle and the bottle is squeezed, the diver sinks. When the bottle is not squeezed, the diver floats. This variant has multiple divers with different densities, as well as a pump to change the pressure in the bottle.
Details
Equipment
- [1] Water bottle with Cartesian diver
- [1] Camera, if necessary
Classroom Assembly
- Arrange the bottle so it is visible on the camera.
Script
- Pump air into the bottle as desired.
- Squeeze the bottle until the diver sinks.
- Let go of the bottle so the diver floats.
- Unscrew the pump to release the pressure.
Additional Resources
References
- PIRA 2B40.30
Disclaimer
- Don't attempt this at home!
Last revised
- 2023
Technicals
- The divers have different volumes of liquid (likely water with food colouring) in each. The divers, from least to most liquid (and lowest to highest density), are yellow, green, red, and blue.
Related AV
Related demos
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.