Re: R = V/I ?

[brian whatcott <inet@INTELLISYS.NET>]

At 14:35 5/9/00 -0400, Michael Edmiston wrote:
> ...   Jim Green is correct that power dissipation can occur in many devices

> ... the power supplied/received by a battery is not I^2*R

> ... Hence, when we supply power to recharge a battery, some
> of the power goes into the chemical reaction, and some of the power goes
> into thermal energy.
>
> Michael D. Edmiston, Ph.D.

It seems to me that Michael is a natural-born educator, with a motivation
to encapsulate an understanding of the sometimes divergent views expressed
 here.

I will touch on one idiom he uses (quoted above) that is not untypical of
that used by electrical engineers: what a PHYS-L contributor might call
 - on a bad day - the reification of power.

Engineers  are indeed wont to assign values to the power of a device.
 They know of course that power is a rate of transforming energy.
 They talk of power dissipation when they know the concept they have
in mind is energy dissipation.

   I can almost hear Jim abjuring the phrase, "...the power received by a
battery..."   I expect it would be a natural target for him, a usage quite
comparable to 'heat' incautiously used, (though energy and heat are the
analogous units.)

Brian W




brian whatcott <inet@intellisys.net>
Altus OK