Re: Missing Energy

[Mark Sylvester <msylvest@SPIN.IT>]

At 12:22 20/05/99 -0500, JACK L. URETSKY (C)1998; HEP DIVISION, wrote:
> Hi J. Epstein-
>        You write:
> ***********************************************
> Seems to me you have to do work to bring the two capacitors together
> (from infinity -- since they are initialy viewed as independent.
> J. Epstein
> *******************
>        So do you conclude, as I do, that there is no issue of
> "missing energy" because the closed system in which energy
> is conserved consists of the two capacitors and the person
> (or device) that brings the two capacitors together?  The
> person must exert a force to combine the two plus leads and
> the two minus leads.
>        Thank you.
>                        Regards,
>                                Jack


Yes but the final energy is LESS than the initial energy, so I don't see
how this helps. Perhaps we're thinking about different problems.

I usually tell people to put a resistor in the circuit, and find how much
dissipation there is in the resistor when the switch is closed. Then try
with a smaller resistor.

The next question is what if the capacitors are superconducting. I tell
them to wait until we've done L-C circuits and then tell me the answer.

Or I should say I used to. The new IB program no longer does capacitors, so
we've lost a bit of what I used to regard as fun stuff.

Mark

Mark Sylvester
United World College of the Adriatic
34013 Duino TS
Italy.
msylvest@spin.it
tel: +39 040 3739 255