RE: some of the reason why energy and power definitions are confusing

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "rb" <randyaz-at-cableone-dot-net> 

Since we are taking this to the sub-atomic level consider this...


"An electron volt (eV) is the energy that an electron gains when it travels
through a potential of one volt. You can imagine that the electron starts at
the negative plate of a parallel plate capacitor and accelerates to the
positive plate, which is at one volt higher potential."

Numerically one eV equals 1.6x10-19 joules or a joule is 6.2x1018 eV. For
example, it would take 6.2x1020 eV/sec to light a 100 watt light bulb.

The 6.41418*10^18 electrons you cited is the quanity of electrons that
passed a certain point in space in a certain amount of time given that a
coulomb is defined as the quantity of electricity passing in one second
through a circuit in which the rate of flow is one ampere.  In your
equation, you were able to remove the time/distance from the coulomb, but,
you didn't account for the time/distance used in defining the volt.

Seems we cant get away from time/distance in attempting to describe energy
doing or acting on something.  Even E=mc^2 utilizes time/distance in the
constant as the velosity of light.

Energy is potential until it becomes kinetic.  Once it becomes kinetic it is
expended in doing work. The amount of work is then described in terms of
power...

Whew... I'm going to go watch my TC make sparks and be in awe just as the
caveman was with fire!


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, June 24, 2004 8:00 PM
To: tesla-at-pupman-dot-com
Subject: some of the reason why energy and power definitions are
confusing


Original poster: "Alfred Erpel" <alfred-at-erpel-dot-com>

Howdy all,


A coulomb is (to me) an unsimplifiable property of the universe.  It is
6.41418*10^18 electrons.  You can't state this in a simpler form another way
in terms of ¹distance, mass, time and energy.  It bugs the hell out of me
that the coulomb in the SI system is defined as a DERIVED unit in terms of
amperes. And amperes has the status of being a basic unit. Amperes is
defined as coulombs/second.  Amperes were INVENTED by man yet have been
confered the status of a basic unit.  This I believe obfuscates and confuses
many issues.  I have no idea why this was done.  It is my opinion that
energy has nothing to do with time, however with this artificial definition,
joules (energy) = watts * seconds.  With this system the energy unit has
time in it and the power unit doesn't.


remember, amps = coulombs / seconds  below and:

joules = watts * seconds

joules = volts * amps * seconds

joules = volts * (coulombs / seconds) * seconds

joules = volts * coulombs


Hence, joules should (IMHO) always be spoken of as being equal to volt *
coulombs. This is a more basic unit and without reference to time.  Power
would be volt * coulombs / second.  This is way less confusing.

If anyone has a clue why the SI system made this exception to defining basic
units, I sure would like to hear it.



¹ distance, mass, time, and energy is it baby, that and nothing else,
comprises all that we know.

Regards,

Al Erpel