Teaching dynamic stability

[Richard]

For the CFIs, what instructional aid do you use--other than the marble and bowl--to teach dynamic stability to a primary student?

 

[cherokeeflyboy]

an egg resting on a horizontal table. An ideal egg has zero stability against motion in one direction: it is free to roll around its axis of symmetry. On the other hand, it has positive stability against motion in the end-over-end direction; if you rock the egg slightly by pushing its nose down, it will tend to return to its original state.