Abstract
The amount of curl of a curling stone can be correctly described by a quantity, curl ratio, which is defined as the ratio of the curl distance and the sliding distance. Measurements of curl ratio were made by use of an actual curling stone on a curling ice sheet. We obtained positions, angles, and translational and angular velocities of the center of mass of a stone by applying the image processing technology to sequential images taken by two CCD cameras. The analyses showed that the curl ratio increased with decreasing translational velocities and with increasing angular velocities. The friction coefficient of ice decreased with increasing translational velocities, roughly with ‒0.5 power, but showed much stronger decreasing tendency at higher angular velocities.
