Re: CONSERVATION OF ENERGY

[brian whatcott <inet@intellisys.net>]

At 21:45 7/15/97 EDT, Ludwik wrote:
> ... why is work equal
> to zero. He [I] did calculate the net (frictional) force acting on the cube
> and the distance over which this force was acting. Why is work zero?

As far as I can see, the partition of the available kinetic energy 
beween heat and work is indeterminate.
 Work may well be expended in deforming asperities of the bearing
 surfaces of the block with the slide - or the frictional coefficient 
may be accounted for by viscous losses in some quasi lubricant layer.
  As it happened, I modeled the deceleration energy as dissipated in heat.
    If there had been some acceleration of the heavy base, then a more 
evident work component would have been present, in my view.


> And I suspect that Leigh will repeat what he wrote about heat on Sunday
> evening. He wrote "Certainly heat plays no role in the process; no energy
> is transferred between the blocks imelled by temperature differences."

I am willing to listen to reason on this effect.
It seemed to me that the frictional energy might be equally shared
 between the block and the substrate, in which case, the block would 
have become warmer than the substrate unless they were in quite 
intimate thermal contact.

> By the way, I see the accepted thermodynamic definition of heat in this
> quotation. This is not the same thing as c*m*dT, which he also called
> heat. I agree with Leigh that we have lingustic problems in this area.
> Do you think some progress was made in our debate to resolve these
> problems?
> OK, perhaps I should say I have problems. These have nothing to do with
> the fact that English was not the language in which I was "schooled".
>
>                                         Ludwik Kowalski

I  too am concerned by the heavy weather we make of this topic.
It is sad that the people who appear to have the most intimate
background in thermodynamics are also the most guarded.

  This is of course an indicator that the waters hereabout may
well be shark-infested.
  To stretch this metaphor yet further, I can imagine that when
the blood of the Copenhagen group puts a ruddy tinge on workable
concepts like energy and work, it behoves physics professionals to 
keep their limbs well inboard...

Regards
brian whatcott <inet@intellisys.net>
Altus OK