NEW ZEALAND PHYSICS TEACHERS' RESOURCE BANK

Spinning Rattleback

Momentum is conserved ...

... and so is angular momentum!

Abstract
Conservation of angular momentum is explored with the strange behaviour of the spinning rattleback by operating it on an air table.
Portable Yes
Principles Illustrated
The apparently magic spinning rattleback changes its direction of rotation when spun clockwise but not when spun counterclockwise. It will start spinning when one end is pressed and released. How is this consistent with conservation of angular momentum? When the rattleback is operated on a plastic sheet on an air table it becomes clear how angular momentum is conserved.
NCEA & Science Curriculum
PHYS 3.4 and tertiary
Teacher Guide
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Video
Instructions
The plastic sheet should have a moment of inertia that is comparable to the moment of inertia of the rattleback, and you need quite a lot of air flow. Our air tables are portable with some difficulty but we will bring them to Wellington area schools.
References
Credits

This teaching resource was developed with support from

 

This video was produced by Victoria University Stage One Students (first year university students) Bethan Cropp and Huyen Nguyen with limited help from staff. High school students and university students are welcome to submit resources. Contact us for details.

The development of this resource was supported by the MacDiarmid Institute.

Copyright

Copyright and fair use statement