Before you are two balls, one solid and one hollow. They are to all appearences completely identical: same size, same weight, same outer material (though one might assume, correctly, that the hollow ball would need a higher-density material on the inside to make it the same weight).
Without breaking either of the balls, how can you easily determine which is hollow?
Assume that the material is solid enough that a hitting the side of the hollow ball will not result in any noticeable echo or vibrations.
I've just been in the store to buy two theoretical cats... prices are really up by now! I live on the nineteenth floor.
Posted by armando
on 2005-03-25 19:11:20