乒乓球运动员为了用球拍打出旋转程度大的球,并不是单纯的切薄,而只能是用适当切薄原理来达到此目的的。该原理已在实践中为乒乓球运动员自觉或不自觉地应用,因此,有必要从理论上进行研究,以利于提高应用它的准确性和能动性。一、变化切薄过程中所出现的两种摩擦力如图一所示,拍面对球的平均作用力点为A,拍 Table tennis players in order to use a racket to play a large degree of rotation of the ball, not simply cut thin, but only by using the appropriate cut thin principle to achieve this goal. This principle has been applied in practice to table tennis players consciously or unconsciously. Therefore, it is necessary to conduct theoretical research in order to improve the accuracy and initiative of applying it. First, the change in the process of thinning the two kinds of friction shown in Figure 1, the average force of the ball on the face is A, beat