Dusko Bjelica1, Marija Bubanja1, Jovan Gardasevic1
1University of Montenegro, Faculty for Sport and Physical Education, Niksic, Montenegro
The Dependence of Repulsion Tennis Ball from the Air Pressure in it
J. Anthr. Sport Phys. Educ. 2018, 2(4), 77-82 | DOI: 10.26773/jaspe.181014
Abstract
The aim of this study is to determine the elastic (reflective) properties of the tennis ball depending on the air pressure in it. The standard tennis ball was released on a flat, solid surface from a height of nine meters, three times. For a tennis ball pressure was measured based on the time and rebound of the ball after the first, second and third falls. In the first release the air in the ball was under prescribed pressure. After the first release, the pressure in the ball is reduced by the fact that the ball once is stabbed with a hollow medical needle, after the second release, the pressure in the ball is reduced further by the ball being pierced twice with a hollow medical needle. The setting of the experiment was done by filming the free fall of the prescribed tennis balls and a series of rebounds after being rejected from a solid surface. It can be concluded that the distance traveled and the total duration of four successive reflections largely depended on the internal pressure. In this study, the initial tennis ball velocity was unchanged and only internal pressures were changed. It was determined how much the rejection rate was reduced and the duration of the re-acceleration, depending on the reduction of the internal pressure. All in all, it can be concluded that the initial speed of the ball can be increased by increasing the internal pressure in the ball.
Keywords
Tennis, Ball, Repulsion
View full article
(PDF – 975KB)
References
Bjelica, D. (2005). Sistematizacija sportskih disciplina i sportski trening. Podgorica: Crnogorska sportska akademija.
Bjelica, D. (2008). Sportski trening. Nikšić: Fakultet za sport i fizičko vaspitanje.
Bjelica, D. i Fratrić, F. (2011). Sportski trening: teorija, metodika i dijagnostika. Nikšić: Fakultet za sport i fizičko vaspitanje.
Bjelica, D. (2014). Repulzija sportskih lopti naučna studija. Podgorica: Crnogorska sportska akademija i Univerzitet Crne Gore.
Bjelica, D., Popović, S., Gardašević, J., & Krivokapić, D. (2016). Dependence of Football Repulsion on the Pressure Within This Sport. Journal of Physical Education and Sport, 16(2), 452-8.
Bjelica, D., Popović, S., & Gardašević, J. (2016a). Dependence of basketball repulsion on the pressure within this sport. Journal of Physical Education and Sport, 16(1), 125-31.
Bjelica, D., Popović, S., i Gardašević, J. (2016b). Modeli fizičke pripreme vrhunskih sportaša i doziranje opterećenja. Zbornik radova 14.godišnje međunarodne konferencije „Kondicijska priprema sportaša” (185-189), Zagreb: Udruga kondicijskih trenera Hrvatske.
Bjelica, D., Popović, S., i Gardašević, J. (2016c). Opći principi planiranja i programiranja fizičkih priprema sportaša. Zbornik radova 14.godišnje međunarodne konferencije “Kondicijska priprema sportaša” (190-192), Zagreb: Udruga kondicijskih trenera Hrvatske.
Bjelica, D., Popović, S., & Gardašević, J. (2016d). Pressure dependence of handball repulsion within this sport. Journal of Physical Education and Sport, 16(2), 1078-83.
Bjelica, D., Popović, S., Tanase, G.D., & Gardašević, J. (2017). Dependence of female ball in handball repulsion on the pressure within this sport. Acta Kinesiologica, 11(1), 67-72.
Bjelica, D. & Gardašević, J. (2018). Volleyball elastic properties depending on ball pressure. Sport Science, 11(1), 45-51.
Filipčič, A. (2007). Kineziološka analiza tenisa - interni materijal za studente. Zagreb: Kineziološki fakultet.
Gardašević, J., Vasiljević, I., & Bojanić, D. (2015). Six-week preparation period and its effects on coordination transformation with football players under 16. Book of Abstracts 11th InternationalScientific Conference Management, Sport, Olympism (36), Beograd: Fakultet za menadžment u sportu, Alfa univerzitet.
Gardašević, J., Bjelica, D., Milašinović, R. & Vasiljević, I. (2016). The Effects of the Training in the Preparation Period on the Repetitive Strength Transformation with Cadet Level Football Players. Sport Mont, 14(2), 31-3.
Gardašević, J., Bjelica, D., & Vasiljević, I. (2016a). Six-Week Preparation Period and its Effects on Transformation Movement Speed with Football Players Under 16. Sport Mont, 14(1), 13-6.
Gardašević, J., Bjelica, D., & Vasiljević, I. (2016b). The Effects of the Training in the Preparation Period on the Repetitive Strength Transformation with Cadet Level Football Players. Book of Abstracts of the 13th International Scientific Conference on Transformation Processes in Sport “Sport Performance” (43), Podgorica: Montenegrin Sports Academy.
Gardašević, J., Bjelica, D., & Vasiljević, I. (2017a). The strength of kicking the ball after preparation period with U15 football players. Book of Abstracts of the 14th International Scientific Conference on Transformation Processes in Sport „Sport Performance” (65-66), Podgorica: Montenegrin Sports Academy.
Gardašević, J., Bjelica, D., & Vasiljević, I. (2017b). The Strength of Kicking the Ball after Preparation Period with U15 Football Players. Sport Mont, 15(2), 39-42.
Milanović, D. (2010). Teorija i metodika treninga. Zagreb: Kineziološki fakultet.
Sermaxhaj, S., Popović, S., Bjelica, D., Gardašević, J., & Arifi, F. (2017). Effect of recuperation with static stretching in isokinetic force of young football players. Journal of Physical Education and Sport, 17(3), 1948-53. https://doi.org/10.7752/jpes.2017.03191.