Abstract
The spin of a tennis ball during play is an important factor. There are two kinds of racket strings, one that causes the ball to spin, and the other makes spinning difficult. The relationship between the spin behavior of a tennis ball and the mechanical properties of the strings is discussed. Rotations of the ball after impact are observed by high-speed photography. The rotational speed of the ball increases with the impact speed, and the speed depends greatly on string type. The frictional characteristics of the strings and ball are measured by an apparatus that reveals a good correlation between the static coefficient of friction of the strings and the spin of the ball when the impact speed is low. Spinning behavior is predicted by measuring the coefficient of friction for the strings. The tenden cies of the measured frictional characteristics agree with sensitivity evaluations by users.
Get full access to this article
View all access options for this article.