抄録
It is said that rubber-ball baseball is lower score game than baseball. The reason is that coefficient restitution of rubber-ball is smaller than that of baseball ball. One more factor is aerodynamic characteristics. Therefore, in this study rubber-ball and baseball ball was rotated highly and measured aerodynamic forces in the similar real flight situation. We analyzed flight trajectory of rubber-ball and baseball ball in cases of pitching and batting by using measured aerodynamic forces. It is found that coefficient of lift and coefficient of drag of rubber-ball are smaller than those of baseball ball. Therefore trajectory of rubber-ball is lower than that of baseball ball. Moreover batting distance in one case that gets home-run distance of rubber-ball is smaller than baseball ball. It is caused by lower coefficient of lift of rubber-ball.
