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Re: Swartz letter in AJP (work-energy theorem)



At 09:29 30 08 2004 , the following was received:
This is mostly a heads-up regarding a letter to the editor from Clifford
Swartz regarding the Work-energy theorem in the new issue of AJP (Sept.
'04).

I was a little disappointed by the remarks in response to this post. They
seemed to say something like -- These are new thoughts, I have never heard
them before, I never learned anything like this in college..... I suppose
that Galileo received the a similar response -- no he was thought to be
evil, wicked, bad, and nasty. Swartz is spoken of here as "silly."

Well maybe he doesn't understand work/energy, but most of the list use the
same language.
He has "energy transfers," "one form of energy into another," "energy
can _go_ to and from springs, gravitational fields, electric fields
..." And in the process reifies the imaginary concept of "fields." So his
first problem is that he doesn't understand the work/energy theorem.

Then he attacks friction. Let's take a side bar: consider a cold widget
which is sliding on ice, the widget slows. therefore its level of energy
is decreased. The _only_ way to change the level of energy of a system is
to do work on the system. What then does this work? Obviously it is the
ice. But how? By exerting a frictional force. Hence, friction does
work. And again he does not understand the work/energy theorem.

Isn't it worth the effort to go through the thought experiment. Should one
call him silly and dismiss him out of hand just because these thoughts have
not been heard before.

Just little me over here in my corner of the galaxy.

Jim


Jim Green
mailto:JMGreen@sisna.com
http://users.sisna.com/jmgreen