Re: [Phys-l] ? passive force of constraint

[John Denker <jsd@av8n.com>]

By way of background: I agree that it is completely reasonable to 
discuss misconceptions amongst ourselves in ways that would be 
completely unreasonable in class.  


On 07/20/2007 09:52 AM, Scott Goelzer wrote in part:
> I do not use active or passive terminology in  
> class. I never ask my students to categorize forces as such. 

OK, thanks, that is an important clarification.  

Dan Crowe made the same point.  And nobody on this list has
argued otherwise.

Given this clarification, I see that my question about "inmates
running the asylum" was based on a mostly-wrong assumption, so I 
mostly retract the question.

Let me explain why I needed clarification as to where list members 
were coming from.  Possibly my first exposure to the active/passive
business was in Arons, _Teaching Introductory Physics_.  I quote 
from page 76:  
    "... it turns out to be helpful for students to distinguish 
    between two classes of forces, designated as 'active' and 'passive,' 
    respectively."

So you can see why I needed clarification.  Arons says it is "helpful
for students to distinguish ...."  Absent the recent clarification, you 
can see why I thought lots of people were teaching this to students.  
I'm not completely crazy, just occasionally confused.

Tangential remark:  I find this to be pretty much par for the course for 
Arons' book.  Given the number of good ideas, it's surprising to see so
many bad ideas mixed in.