Laws of Rolling Friction

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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 = _r L/r, where _r 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.