Abstract
Purpose. The purpose of this study was to analyze and compare the variables associated with successful long jump performance. Specifically the purpose of this study was to investigate the optimum angle of projection and the vertical force available at take-off in the performance of the long jump. Procedures. Five high school athletes served as subjects for this study. These subjects were selected solely on the basis of their ability to long jump a distance of 21 feet. The subjects performed before the camera following instructions to vary the approach velocity while trying to attain maximum height at take-off. The performances were filmed using one camera placed at a right angle to the path in which the subjects performed. The camera was a 16mm Bell and Howell with the filming speed set at 64 frames per second. The filming speed was checked and corrected to 57.8 frames per second. The variables of maximum horizontal velocity, horizontal velocity at take-off, angle of projection, and height of the jump were determined from the film with the use of a Vanguard Motion Analyzer. The vertical velocity at take-off and the observed velocity at take-off were computed using the horizontal velocity and the angle of projection in conjunction with the appropriate trigonometric functions. The available effective force (vertical) at take-off was calculated using the momentum formula of mass times velocity. It was assumed that the force available at take-off is equal to the subject's body weight plus the momentum (change in force from a horizontal direction to a partially vertical direction). The distance jumped in each trial was measured using a steel tape.
Jubela, Robert Otto (1981). Angle of projection and available force in the long jump. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -647902.