ad exercise 10.2

I understood that the description of the setup for the bowl on the
turntable was not clear from the description.  Hence, I added a sketch
to the problem rather than asking you to figure out what I have in
mind:
The bowl is placed on the turntable and rotating with a given
frequency \Omega. The purpose of the exercise is to discuss the motion
of the ball -- and given that we disregard effects due to friction and
the rolling of the ball this is a point particle moving in a potential
well giving rise to a specified force pointing into the direction of
the rotation axis.

I hope this helps to clarify what I have in mind.