Friction

[Vince Mrykalo]

> Larry Fine asked:
> > I'm surprised to hear that friction is independent of the contact area.
> > Could you please explain why this should be so, counter-intuitively?
> >
> An intuitive explanation of this may be had by thinking of the
> molecular forces which cause friction. Consider static friction,
> which applies when there is no relative motion between 2 surfaces. On
> a very small scale the surfaces appear very bumpy and where the bumps
> coincide the contact area is `cold-welded'. It is these bonds which
> must be broken to break the frictional contact between the surfaces.
> The minimum force required to break these bonds is independent of
> how many there are i.e. the surface area of contact. [Intuitive
> reasoning only here as requested.]

Intuitively speaking, it seems to me that the more bonds there are,
the more force would be required to break them.

---
vince mrykalo  rpt

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The facts all contribute only to setting the problem, not to
its solution -
Ludwig Wittgenstein

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