Re: [DSII] Genre - and details about casting/moulding

>Actually I don't think its either.  Centrifugal force is a "fictional"
>force.  Centripidal refers to the "center seeking" acceleration of an
object
>moving in a curved path(I think).  I would say the air is forced out
because
>the metal or whatever, wants to move in a straight line, but the mould
>prevents it, so it does the next best thing and flows into  the mould
until
>it can't go any farther.  Anything less dense than it is pushed out of
>wherever it happened to be flowing.
>
>Hot damn, that dynamics class was actually useful......of course I
could be
>wrong.
>
>
>Christopher K Smith

Well, that's what I meant... :)  This "fictional" force is the same one
that holds water in a bucket as you swing it around over your head...  I
know the physics of it, you know the physics of it - we're talking about
the same thing... but instead of saying "we accelerate the metal up to x
speed in the spinning mould, and it's inertial tendancy is to move in a
straight line in the direction of the acceleration vector but can't
'cause
the mould is in the way so it moves along the route of least resistance
further into the crevices in the mould forcing the air out 'cause the
metal
is more dense, yadda yadda yadda"  we use the shorthand term
"centrifugal
force".  Yes there isn't really a force there.	Everybody has swung a
bucket of water around their head, though, and knows exactly what we
mean.

Except physicists, who just have to make things complicated...	:)