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

["Dan Crowe" <Dan.Crowe@Loudoun.K12.VA.US>]

The only reason for the labels "active force" and "passive force" is the
misconception, shared by many students, that only animate objects are
capable of exerting forces.  Physics educators use these labels when
discussing this misconception.  We need to be aware that many of our
students have this misconception, and we need to address it by using
pedagogies that lead students to conclude that inanimate objects are
capable of exerting forces, but we should not teach students the labels
"active force" and "passive force", because, as John notes, that would
only reinforce the misconception.

I don't understand Scott's statement that there are no passive forces.

Daniel Crowe
Loudoun Academy of Science
dan.crowe@loudoun.k12.va.us
> > > jsd@av8n.com 07/19/07 8:54 PM >>>
On 07/18/2007 09:50 PM, Dan Crowe wrote in part:
> >  an active force is a force exerted by an animate organism 

On 07/19/2007 04:29 PM, Scott Goelzer wrote in part:

> Ideally, all students would come to realize that there are no passive 

> forces.

OK, now I'm even more confused than when we started.

Am I to conclude that all forces are exerted by an animate organism?

I'm not trying to be difficult;  I just can't see any other way to
interpret what I'm being told.  Is there a typo somewhere?

The more I learn about passive forces and active forces, the more I
want to stay away from them.

> The concept is not DOA  
> since it exists for students. 

Why should we let the inmates run the asylum?  I'm not shy about
confronting misconceptions when necessary ... but I see no reason
to think this active/passive business is necessary.  Discussing a
previously inchoate misconception will often consolidate it rather
than dispelling it.  Not to mention the time spent discussing it.