Re: ENERGY WITH Q

["Carl E. Mungan" <mungan@USNA.EDU>]

> That is why I prefer to introduce the First Law WITHOUT
> addressing the issue of how the energy "traversing the system
> boundary" (flowing, transmitted, going, drifting, shifting, or
> penetrating, if you prefer) can be subdivided into two, three
> or more components. This topic should be debated in a more
> advanced course. IS THIS ACCEPTABLE?

Yes, I basically agree.

My view is there are 3 topics to present to students. All 3 need to
be covered. So far I am unconvinced there is a compelling reason to
diverge significantly from the "standard" order most texts follow:

1. Mechanics problems. Here we introduce the ideas of work, KE, PE,
etc. We solve problems like pendula, blocks sliding on rough tables,
children going down slides (with and without friction), etc. We do
lots of problems and as little theory as possible because the kids
already are supposed to know about kinematics and dynamics, which is
what this is all based on. Key equation: work-energy theorem.

2. Big picture about energy. Here we discuss the idea of energy being
conserved in general. We give long lists of different kinds of
energy. We introduce the idea of internal energy. We talk about
transferring energy from one system to another, and about changing
its form from one kind to another. We tell the kids why conservation
laws are so important and elegant. We do lots of talking but solve
few actual problems. Key equation: first law.

3. Thermodynamics and problems. We introduce and discuss functions of
state, microscopic degrees of freedom, entropy and heat, ideal gases,
temperature, etc. We do lots of theory AND problems and PRAY the kids
get some of it. Key equation: second law.

> I would very
> much like to add a list of URLs for documents in which energy-
> related topics are described by Phys-L-ers. So far I have only
> three references: JohnD, JimG and JohnM. Who else would
> like to share a web page document devoted to energy related
> issues? Yes, any topics in physics is "energy related." But
> you know what I want. The document should be about kinds
> of energy and about the laws of thermodynamics (for
> student or new teachers of introductory physics courses).

Here's my evolving document, as summarized in many previous postings:
http://physics.usna.edu/physics/faculty/mungan/Scholarship/WorkEnergyTheory.pdf
--
Carl E. Mungan, Asst. Prof. of Physics  410-293-6680 (O) -3729 (F)
      U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5026
mungan@usna.edu    http://physics.usna.edu/physics/faculty/mungan/