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Re: [Phys-l] definitions ... purely operational, or not



What I learned in my freshman year physics class can be summed up like this: if you use English units, your answer will be wrong by a factor of 32 no matter what you do!
________________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu [phys-l-bounces@carnot.physics.buffalo.edu] on behalf of curtis osterhoudt [flutzpah@yahoo.com]
Sent: Sunday, November 07, 2010 9:23 AM
To: Forum for Physics Educators
Subject: Re: [Phys-l] definitions ... purely operational, or not

Oh boy. Sorry about that. The properly-formatted table show up at the "slug
(mass)" link on Wikipedia.


/**************************************
"The four points of the compass be logic, knowledge, wisdom and the unknown.
Some do bow in that final direction. Others advance upon it. To bow before the
one is to lose sight of the three. I may submit to the unknown, but never to the
unknowable." ~~Roger Zelazny, in "Lord of Light"
***************************************/




________________________________
From: curtis osterhoudt <flutzpah@yahoo.com>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Sun, November 7, 2010 7:16:41 AM
Subject: Re: [Phys-l] definitions ... purely operational, or not

The "pound-force" is the accepted weight unit.
(http://en.wikipedia.org/wiki/Mendenhall_Order)

The following table is stolen from http://en.wikipedia.org/wiki/Slug_%28mass%29
:




Three approaches to mass and force units
System
Engineering
Gravitational
Absolute
Force (F)F = m·a F = m·a/gc = w·a/g F = m·a
Weight (w)w = m·g w = m·g/gc ≈ m w = m·g

Units
English
Metric
English
Metric
English
Metric
Acceleration (a)ft/s2 m/s2 ft/s2 m/s2 ft/s2 m/s2
Mass (m)slug hyl pound-mass kilogram pound kilogram
Force (F)pound kilopond pound-force kilopond poundal newton

/**************************************
"The four points of the compass be logic, knowledge, wisdom and the unknown.
Some do bow in that final direction. Others advance upon it. To bow before the
one is to lose sight of the three. I may submit to the unknown, but never to the

unknowable." ~~Roger Zelazny, in "Lord of Light"
***************************************/




________________________________
From: Robert Yeend <ryeend@sbcglobal.net>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Sun, November 7, 2010 7:05:49 AM
Subject: Re: [Phys-l] definitions ... purely operational, or not

As someone who grew up thinking of the slug as the unit of mass and
pound as the unit of weight, what, then, is the accepted unit of weight?

Bob Yeend

On Nov 7, 2010, at 5:34 AM, John Denker wrote:

Recall that the pound is
defined as a unit of mass according to US law, and always
has been.

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l




_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l




_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l