Re: [Phys-L] field of an ellipsoidal distribution

["A. John Mallinckrodt" <ajm@cpp.edu>]

Chuck Britton wrote

> If your table were floating on the surface of a (quiet) lake, the water would not feel a (net) force toward the equator, nor would your air puck.
>
> Right?

In the rest frame of the lake surface, the water would feel no net force, period, by simple application of NII.  

(Of course, in the non-rotating rest frame of the center of the Earth, that same water would experience a net force toward the Earth's axis of rotation, again by NII.  I suspect, however, that you are thinking about the rest frame of the lake and the rest of my comments are predicated on that assumpton.)

A puck sliding freely and frictionlessly on the table top will experience no net force ONLY if the table top is parallel to the lake surface, which I suspect you are assuming.  It's worth noting, though, that most tables don't float that way!

John Mallinckrodt