PIRA Classification: 1J20.17
Description: A large block is placed on a cylindrical surface. It stays on (stable). The block is then placed on a parabolic surface. It slides off (unstable). The block is finally placed on a catenary. The block will balance at various points on the curve, as in the movie above (neutral).
Special Instructions: This takes a little practice.
Condition: OK
Setup time: 1 minute
Safety Issues: None