Scott Gardner wrote:
> I give you two cylinders, both identical in appearance and weight.
> One is made of aluminum, and is solid. The other is made of gold,
> and has the center hollowed out (outside surfaces are unbroken,
> however.) Both are painted an identical non-conducting British
> Racing Green (obligatory lame attempt at LBC content).
> Performing only non-destructive testing, with materials/methods
> available in the typical household, how can you tell which cylinder
> is which? Tapping on the cylinders with a mallet produces identical
> sounds.
Weigh them. The gold one will be lighter, because Gold is
measured in Troy weight.
Similar to the "which is heavier, a pound of feathers or
a pound of gold" question.
(even non-trick questions deserve trick answers)
In the real world though, you could spin them into each
other and note the rebound. The gold one will have a higher
moment of inertia because of peripheral weighting.
--
Trevor Boicey
Ottawa, Canada
tboicey@brit.ca
http://www.brit.ca/~tboicey/
|