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Re: [Phys-l] rolling friction



I would add to this list:
e) dissipative force arising from any "sticking" between the tire and the
road surface at the trailing edge of the tire; as the tire lifts away from
the road surface, it may need to be "ripped off" of the road to continue
the rotation. Note that friction associated with a very sticky tire is
not covered by any of the four choices below.

This is the mechanism that I have usually heard referred to as rolling
friction.

jg


For starters, there are at least _four_ different notions of friction
that apply:
a) friction transverse to the rolling, which prevents the tire
from skidding sideways. This is important during cornering.
b) friction along the direction of roll, which prevents the
tire from spinning freely. This is particularly important
during acceleration from a stop.
c) friction that causes dissipation during rolling.
This includes internal friction in the sidewall as
it flexes, plus some sliding friction as different parts of the
footprint squirm relative to each other and therefore relative
to the road.
d) Dynamic friction during outright skidding.

Josh Gates
___________________
Noble and Greenough Physics
Dedham MA