Re: [Phys-L] force-pair question

["Bob Sciamanda" <treborsci@verizon.net>]

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/
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Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
treborsci@verizon.net
www.sciamanda.com