Re: CONSERVATION OF ENERGY

[LUDWIK KOWALSKI <kowalskil@alpha.montclair.edu>]

On Tue, 22 Jul 1997 Patrick Whippey <pwhippey@julian.uwo.ca> wrote:

> I have spent the afternoon reading a new text "Physics:  A Contemporary 
> Perspective" by Randall Knight from Cal. Poly at San Luis Obispo, Addison 
> Wesley.  It is one of a new breed of textbooks that are beginning to use 
> the insights that the Physics Education Research Community has brought to 
> our attention.  His discussion of the problem is superb, and I now have 
> new insights into this problem of zero work forces, and where the enrgy 
> goes when a block slides over the table.  I think many contributers to 
> this list would anjoy it too.

Thanks a lot. It is indeed a book which seems to be quite different from
many. As I can see from Chapter 11, the sliding on the horizontal surface
is one of several examples analyzed as an application of the work-energy
relation for a system of particles. Looks promissing, will start reading
carefully now. Here is another example (page 375). 

   A 1000 kg car traveling at 5 m/s runs into a solid, unbending wall.
   The bumper and the front of the car crumple upon impact, resulting 
   in the car's center of mass moving forward before stopping. Analyze 
   and interpret the forces and energy transfers of this collision. 

The entire page is devoted to this problem. The terminology is very much 
in line with what was emphasize in this thread. And how can I resist 
mentionning that 'thermal energy' is in the author's vocabulary? 

I received both volumes of the preliminary 1997 edition. The ISBN codes 
are: 0-201-43164-5 and 0-201-43165-3, paperback. If you are going to
Denver stop at Addison Wesley stand and browse the book. Talk to them; 
perhaps you will also receive a complimentary copy.
                                                        Ludwik Kowalski