Re: work done by friction

[brian whatcott <inet@INTELLISYS.NET>]

At 19:20 10/28/99 -0700, you wrote:
> > Leigh,
> >
> > Does your frictional force act on a line of action passing
> > through the center of mass of both blocks?
> > If not, then don't rotational effects need
> > consideration?
> >
> > Bob Carlson
>
> That's a question I hadn't considered. As you point out, it could
> matter. But it doesn't. ...
> The details of this silly example are unimportant. I just want to
> highlight the fact that it is not always useful to designate a
> particular interaction as being "work". Friction presents problems
> for such analysis; it is not straightforward in the way that other
> analyses are. There are tougher ones, too. How much work is done on
> a river when a canoeist pulls his paddle through the water?
...
> Leigh

I have to say, that I enjoyed this cycle of rebirth of the
friction analysis more fruitful than several previous incarnations.

 Denker's spirited defense of the orthodox position was important.
I read that 'work' need not be strictly conserved hence work on
rubbing surfaces coming to rest wrt each other need not be equal,
evidently an article of faith in some quarters, was quite liberating
as was the reassurance that one could tally its effects in a proper
double entry style.


brian whatcott <inet@intellisys.net>
Altus OK