pining,twin plugging,etc...

[Shannen Durphey]

Lino Verna wrote:

> When you push on a wall with 200lb's of force it
> >> pushes back with the same amount and yet it did not
> >> move,,,hmmmmmm,,,,but it is stored energy
>
> >
> >If you push on the wall and it pushes back, but nothing moves, you've
> >created heat!  Energy dissipates into the air.
>
> >Wouldn't stored load be called inertia?  I seem to remember doing some
> >inertia equations in a physics class.  Can't remember the equations but I
> >sure remember doing them.
>
> Actually the wall does move, and that is how it stores the energy.
> Push on anything and it will move.
>
> Tell you what, put on that cone shaped hat like the rest of us wear and
> jump.
> I guarantee that the earth will move the other way as a reaction to your
> jump.
> That is, only if you're wearing that hat though...
>
> lino

  Ahhh!  But the measure of anything depends on a reference point.  With Earth
as a reference point, only I and my cone shaped hat will move.  When I land,
the Earth is not moving, and much too quickly I am not either.  But I sure
have expended my energy and likely cannot find any of it stored up in the
place where I hit.

Believe me about this.  I have a subscription to the cone shaped hat of the
month club.

Ok, I'll probably get flamed for this, but there are circumstances where
pushing can't cause movement.  There is simply not enough force in the push.
Maybe where I'm getting confused is my idea about "stored" energy.  It seems
that if energy were being stored in the wall, it would be accessible.  Like a
flywheel spinning on a shaft has stored energy.

But how can you measure the energy "stored" in the wall?  Some of you ME types
can surely help me here.  It seems that there is certainly a definition of
pushing without movement.  It's called Force.
And pushing with movement is Work.  ('course pushing without movement can be a
lot of work, too).  So the energy must go somewhere.  In many cases it's heat.
But what about gravity and the telephone supported by my computer table......
If I balance this glass of water like so... ah, but, um,,,

Uh-oh.  My wheels are spinning again.

Time to go re-arrange the hat collection.

Shannen