The purpose of the experiment was to determine the effect of kicking a soccer ball at different impact locations, or strike zones, on the overall distance traveled by a soccer ball. The impact locations consisted of 2.5 inches above, 2.5 inches below, 1.25 inches, and 2.5 inches to the left of the cross sectional center of gravity. The researchers predicted kicking the soccer ball in the center would produce the maximum distance traveled because no energy would be exerted on spin. A spring-loaded apparatus was made to generate consistent energy through the experiment. The trials were performed on a turf soccer field to reduce lurking variables. Before the ball was kicked, the researchers made sure the cleat struck the ball in the specified strike zone. The “leg” was pulled back a constant distance and released to kick the ball. The researchers found the lower strike zone produced the greatest distance while the center strike zone produced the second greatest distance. During the lower trials, the ball flew in the air before hitting the ground causing the ball to lose less energy and travel further because the ball only experienced drag in the air as opposed to balls traveling on the ground which experienced both drag and ground friction. The center impact traveled more distance than the other two horizontal impacts deviated from the center because as the impact location increasingly deviated from the center, the rotational kinetic energy increased and the translational kinetic energy decreased due to the law of conservation of energy. Ultimately, the researchers rejected the original hypothesis. These conclusions can be seen throughout various sports; one example occurs in baseball. Ground balls, hit at the top of the ball, do not travel as far as “home-run” balls which are hit at a lower region on the ball, creating approximately a 45° angle of elevation.

Research Done By:

Guy Lin
Sterling Heights High School

Frank Woo
Lakeview High School