Re: [Phys-l] bound vectors ... or not

[John Mallinckrodt <ajm@csupomona.edu>]

Mike Edmiston wrote:

> I am not sure it is necessary to specify the "point of application"  
> of a force vector.  I think it may be sufficient to specify a point  
> in space that lies on the "line of action" aka the "line of force"  
> of the force.  The point of application could be the point that  
> fixes the force vector in space, but requiring that specific point  
> is probably overly restrictive.  Once any point along the line of  
> action is specified, (along with the magnitude and direction of the  
> force vector itself), the specific point of application becomes  
> irrelevant.

If you want to get the physics right, you have to know exactly where  
the force is applied, not merely the line along which it is applied.   
You also have to know if the point of application or the magnitude or  
direction of the force changes with time.

None of this, however, changes the fact that "force" is a vector and,  
like all vectors, it has magnitude and direction, but not location.

Is it just me or does this thread seem particularly misguided to  
anyone else?

John Mallinckrodt
Cal Poly Pomona