Laws of rolling friction. The laws for
sliding friction cannot be applied to rolling bodies in
equally quantitative terms, but the following generalities
can be given:
(a) The rolling friction force F is
proportional to the load L and inversely proportional to the
radius of curvature r, or F = µr L/r, where µr
is the coefficient of rolling resistance, in meters
(inches). As the radius increases, the frictional force
decreases.
(b) The rolling friction force F can be
expressed as a fractional power of the load L times a
constant k, or F = kLn where the constant k and
the power n must be determined experimentally. n
(c) The friction force F decreases as the
smoothness of the rolling element improves.
