From: utzoo!decvax!ucbvax!npois!harpo!utah-cs!utah-gr!thomas
Newsgroups: net.misc
Title: Re: Two ball problem.
Article-I.D.: utah-gr.429
Posted: Wed May 26 12:42:07 1982
Received: Sat May 29 09:18:36 1982

Well, now, seems to me you could measure the moment of inertia of each ball.
The one with the greater moment would be the hollow one.
=Spencer