Answer:
Explanation:
Forehand groundstroke effectiveness is important for tennis success. Ball topspin angular velocity (TAV) and accuracy are important for fore hand groundstroke effectiveness, and have been extensively studied, previously; despite previous, quality studies, it was unclear whether certain racquet kinematics relate to ball TAV and shot accuracy during the forehand groundstroke. This study evaluated potential relationships between (1) ball TAV and (2) forehand accuracy, and five measures of racquet kinematics: racquet head impact angle (i.e., closed or open face), horizontal and vertical racquet head velocity before impact, racquet head trajectory (resultant velocity direction, relative to horizontal) before impact, and hitting zone length (quasi-linear displacement, immediately before and after impact). Thirteen collegiate-level tennis players hit forehand groundstrokes in a biomechanics laboratory, where racquet kinematics and ball TAV were measured, and on a tennis court, to assess accuracy. Correlational statistics were used to evaluate potential relationships between racquet kinematics, and ball TAV (mixed model) and forehand accuracy (between-subjects model; α = 0.05). We observed an average (1) racquet head impact angle, (2) racquet head trajectory before impact, relative to horizontal, (3) racquet head horizontal velocity before impact, (4) racquet head vertical velocity before impact, and (5) hitting zone length of 80.4 ± 3.6˚, 18.6 ± 4.3˚, 15.4 ± 1.4 m·s-1, 6.6 ± 2.2 m·s-1, and 79.8 ± 8.6 mm, respectively; and an average ball TAV of 969 ± 375 revolutions per minute. Only racquet head impact angle and racquet head vertical velocity, before impact, significantly correlated with ball TAV (p < 0.01). None of the observed racquet kinematics significantly correlated to the measures of forehand accuracy. These results confirmed mechanical logic and indicate that increased ball TAV is associated with a more closed racquet head impact angle (ranging from 70 to 85˚, relative to the ground) and increased racquet head vertical velocity before impact.
Answer:
while it depends on were your eating at and what they are selling. if you want i can help you out more just give me the info of what the place is called and what you want! :)
The Occupational Safety and Health Administration is the department that enforces the standards set out in the occupational safety and health act.
Secret Black Ops missions, and that it's a witness protection program. Hope this helps!
I strongly agree that physical activity has influenced my character. The activity and how it affected me is: Relay Racing it helped me develop a character that accommodates others as well as a good team spirit.
<h3>Meaning of Character</h3>
A character can be defined as a pattern or quality that is peculiar to an individual.
Character are influenced and shaped by our everyday activity and also the people that are around us.
we can conclude by saying, When we engage in physical activities, we get to interact with different individuals and also engage in different activities that tends to shape our characters over time either positively or negatively.
Learn more about Character: brainly.com/question/8864308
#SPJ1
