Re: Loaded dice

[Tim Folkerts <tfolkert@FHSU.EDU>]

> It seems to me the effect of the "loaded" side only
> comes into play when the die is in contact with the
> table. At that point, a net torque is possible (but
> not while the die is in the air) and the die is more
> likely to lie heavy side down.

To a first approximation, the air applies a force at the geometric center
of the object, but gravity applies a force at the center of gravity (hence
the name!).  Since these are at different locations, there must be a net
torque.  But it shouldn't make much difference in the air (see below).

Consider an extreme example of a sheet of Styrofoam with a heavy weight
along one edge.  Clearly(?) that edge will rotate to the bottom as it
falls.

Or consider holding the weighted die with the weight to one side.  Imagine
cutting the die in half and dropping the two halves.  In the presence of
air, the weighted half will have a higher terminal velocity and fall faster
than the unweighted half.  If we then imagine tying the two halves
together, the heavier side will tend to rotate under the lighter half.
However, if you have ever dropped objects of different density, there is
very little difference in velocity between even a Styrofoam ball and a
steel ball over distances of a meter or two.  Hence the small amount of
extra weight in the die can't make much difference in the air.

Tim Folkerts

Department of Physics
Fort Hays State University
Hays, KS  67601
785-628-4501

"The only thing necessary for the triumph of evil is for good men to do
nothing." - Edmund Burke