Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] teaching energy

----- Original Message ----- From: "Rauber, Joel" <Joel.Rauber@SDSTATE.EDU>
To: <>
Sent: Thursday, September 28, 2006 3:51 PM
Subject: Re: [Phys-l] teaching energy

I just made a quick (5 minute) cursory glance at the reference below; it
appears very interesting, however, I'm bothered a bit by the discussion
of gravitational PE on page 3.

| Please read "Making Work Work" at
| <
<> >

The author makes much of saying saying that we won't say there is a PE
associated with the system of two masses, since we can't locate the
energy in either body. Therefore they conclude that it resides in the
gravitational field.

I fail to see what is wrong with associating PE with the system, the
distance between the objects being the state variable. They mention this
interpretation and then reject it.

The central theme is that the energy must reside somewhere. Taken in that context, the only "place" for it to be is in the field itself.

I suppose they must do the same thing when it comes to discussing PE of
a system of 2 charges. I.e. the modelers calculate energy in a charge
configuration by integrating E^2 over a volume, rather than by

Not necessary. The calculation of energy proceeds as usual, it is simply a case of where that energy "resides".