M-CM 7: Forces in circular motion

PIRA: Unknown

Equipment: A wooden arc with a well drilled at each end, covered in plexiglass and which contains two steel balls. This item is in Set 8, Cabinet 2, Shelf 2.

Procedure:

Inside at each end of the wooden arc is a well which can hold a ball. The problem is to get one ball in each well. The angles are such that if a ball is rolled into one of the wells, it will roll out when the arc is tilted enough to get the other ball in the other well. The problem is solved by spinning the gadget at a moderate rate (really rather slowly) about a vertical axis through the natural point of contact on the table. Each ball flies out and falls into its respective well.