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Dario wrote:
A few days ago, JGreen asked * is the work/energy absolute ?
I was no able to answer since I have no idea what * absolute *
means. However I share with you a question I invented and use
in home-works. It may be related to Green's question. But even
if it does not, it is fun.
-----------------------------------------------------------
THE QUESTION:
Charles in riding a train and watching the outside panorama.
He notices a specially beautiful tree and been a student of
physics, thinks: "that tree has kinetic energy".
After a while, the train stops and looking the same tree again,
Charles thinks: "Now the tree is at rest ! Since there are no
changes in the potential energy of the tree, where dit it's
kinetic energy go?"
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Dario Moreno
Ancora Bravo!
Another good example of the pseudo problems one will struggle to
solve if one endows every mathematical entity (energy, force . . . )
with a substantive existence so that it becomes endowed with properties
such as position and velocity. Eg.: the velocity v in P=F.v is a
property of the object experiencing F; it is not a property of F (which
is not a substantive entity).