[CAUT] Friction (was restrung D)

[Ken Zahringer]

That's exactly right, Dave.  As the Wikipedia article points out, the force
of friction is dependent on both the coefficient and the contact area.  Of
course, it also points out that in nearly all cases of two flat surfaces the
contact area is such a small factor that it can safely be neglected.  Two
instances when it cannot be neglected concern surfaces with adhesive
properties and lines wrapped around cylinders.  In these cases the maximum
force exerted by static friction can change significantly with a change in
contact area, given a constant normal force and coefficient.  Hence the
importance of that factor when dealing with tires and piano strings.

Regards,
Ken Z.


On 4/17/07 9:50 AM, "Porritt, David" <dporritt at mail.smu.edu> wrote:

> Ken:
> 
> I think I could have expressed my thought better if I had said that the force
> needed to overcome friction is increased with more contact area.  The friction
> coefficient wouldn't necessarily change, but the force needed to overcome it
> would.
> 
> dp
> 
> David M. Porritt
> dporritt at smu.edu
> 

-- 
Ken Zahringer, RPT
University of Missouri
School of Music