Re: There's work, and then there's work

[Bernard Cleyet <anngeorg@PACBELL.NET>]

"Suppose we have a C = 1000 microF cap initially charged to Vo = 10 V
that is discharging through a small R = 10 ohm resistor and L = 20 cm
of copper wire with a diameter of d = 1.00 mm.

Using the density of copper (rho = 8.9 g/cm^3), the atomic mass of
copper (M = 64 g/mole),  and the assumption of one conduction
electron per copper atom, we find a conduction electron number
density of n = (rho/M)*N_avog = 8.5 x 10^22 electrons/cm^3 and a
total of N = n(pi*d^2*L/4) = 1.3 x 10^16 conduction electrons."

Just a nit: I think the N is closer to 10^21 electrons in the wire.
Otherwise I very much appreciate the post.

bc who may be missing something, but the 16 vs. 22 did "stick out".

John Mallinckrodt wrote:

> Robert Cohen wrote:
>
> > I would like to respond to David Rutherford's argument that energy
> > is associated with both the heat gained by the surroundings (via
> > what he calls the transverse component velocity) and the kinetic
> > energy associated with the current (which he relates to the
> > longitudinal component velocity).
> >
> > This is actually a common source of confusion for my students and so
> > I would like to see it better addressed than it has.  DR is right
> > that, at any given time, only part of the energy (associated with
> > the kinetic energy of the electrons) will be converted to heat as
> > measured by the calorimeter experiment.  However, the key point that

cut