A ball that rolls on carpet while also spinning around a vertical axis will experience a drift force that acts perpendicular to its velocity, opposite to the tangential velocity component of the front point of the ball. Here, we present a model of this motion based on three assumptions: the ball rolls without slipping around the point of contact directly below its center of mass; the ball experiences rolling resistance due to a forward-shifted normal force; and the ball experiences a forward-shifted kinetic friction (drift) force. This model produces a simple analytic solution that is consistent with experimental data. Our measurements suggest that the kinetic friction force acts near the front of the contact patch between the ball and carpet. 2023 Publishedunder an exclusive license by American Association of Physics Teachers.
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