Effects of velocity, surface, and angle of incidence on angle of rebound of tennis balls

Abstract

The purpose of this study was to determine and compare the effects of velocity, surface, and angle of incidence on angle of rebound and velocity of rebound of tennis balls. More specifically, it was the purpose of this study to: (1) determine the effect of incidence angles of 20°, 30°, 40°, 50°, 60°, 70°, and 80° on the angle of rebound and rebound velocity of tennis balls, (2) determine the effect of incidence velocities of 59 feet per second, 62 feet per second, and 86 feet per second on the angle of rebound and rebound velocity of tennis balls, and (3) determine the effect of Laykol court composition Tartan smooth court composition, and hardwood gymnasium court composition on the angle of rebound and rebound velocity of tennis balls. A total of 102 observations were recorded by use of a Locam high speed camera operating at 200 frames per second as the angle of incidence, velocity of incidence, and surface crossovers allowed for 21 experimental cells per surface. Thirty observations were taken on the Laykol surface, 36 on the Tartan smooth surface, and 36 on the hardwood gymnasium surface. A general linear models procedure was employed to test the null hypotheses of no differences in angle of rebound and velocity of rebound due to the independent variables. R-squares were determined in accounting for the various variations in the dependent variable attributed to the independent variables. Analysis of variance and Student Newman-Keuls techniques were also commanded in the data analysis. The angle of rebound was determined to be different from the angle of incidence. In all 102 cases, the angle of rebound exceeded the angle of incidence. Deviations in the angle of rebound were all positive and they ranged from +1.50° to +13.00°. The velocity of rebound was determined to be significantly slower than the velocity of incidence. In all 102 cases, the velocity of rebound was less than the velocity of incidence. The rebound velocity was found to be a mean 62.43% of the incidence velocity. The following conclusions were established based on the results and limitations of this study...