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Re: [Phys-L] force-pair question

Hi all,

- Understanding this seems to be akin to understanding a living-natural
example of it - the fighting of the rams:


http://www.bing.com/videos/search?q=mountain+goat+fighting+ram&FORM=VIRE1#view=detail&mid=D6C812494BE83B39B4B4D6C812494BE83B39B4B4

- One can see (or maybe even speculate) that the time they spend thinking
between the head rams is spent entirely on ascertaining that indeed the
resulting forces will be equal and opposite.

Where are their brains?

Bill Norwood, U of MD at College Park


On Wed, Jan 7, 2015 at 2:20 PM, Bob Sciamanda <treborsci@verizon.net> wrote:

Yes indeed! The discussion always blossoms into scenarios marveling at
the weird, unassisted motions that would result from various unequal (in
magnitude and/or direction) force pairs. The driven point is (akin to 2nd
law of thermo motivational arguments) that we never see such unassisted
phenomena.

-----Original Message----- From: John Denker
Sent: Wednesday, January 07, 2015 1:50 PM
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] force-pair question

On 01/07/2015 11:05 AM, Bob Sciamanda wrote:

In teaching motivation for the third law I have found unfailing
success in "Socratically" uncovering a scenario like ==> "Suppose I
had an object A which repelled another object B, without object A
experiencing any force. I could then fasten them in-line on the
floor of my little red wagon and magically achieve effortless and
free self-locomotion."


That's one scenario.

Here's another: Suppose the effect was not intrinsic to
the objects. Instead suppose that the object on the north
side always accelerated differently from the object on the
south side. That would have some spectacular consequences
such as
uheevpnarf gung nyjnlf fcva ppj (va gur abegurea urzvfcurer).

Hint decoder: http://www.rot13.com/
_______________________________________________
Forum for Physics Educators
Phys-l@www.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l

Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
treborsci@verizon.net
www.sciamanda.com
_______________________________________________
Forum for Physics Educators
Phys-l@www.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l