Conservation of angular momentum is explored with the strange behaviours of the spinning rattleback by operating it on an air table. See video below.
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.
Download video (right-click and “save link as”): Spinning Rattleback.m4v
NCEA & Science Curriculum
PHYS 3.4 and tertiary
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.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
Would you like to contribute lesson suggestions? Contact us.
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.
The development of this resource was supported by the MacDiarmid Institute.
This teaching resource was developed with support from