scalpitch

The Float Serve I am a volleyball player and also currently taking Physics in my last year of high school. I am trying to explain the odd trajectory that a volleyball follows when it is served a certain way. The Main Idea: A float serve is implemented in the game of volleyball to make it as difficult as possible for the opposing team to effectively receive and play the ball. By contacting the center of the ball with a hard hand and not following through with the swinging arm, the ball follows a very odd trajectory through the air, making it appear as if it were floating through the air (traveling side to side, up and down, and curving) WITHOUT any kind of spin. It's pretty cool!! The Factors: To explain this odd trajectory in it's entirety is quite a task. It can be explained by the fact that the hand-to-ball contact alters the ball's form and the air resistance changes it's otherwise straight trajectory as it is no longer a perfect sphere. The recoil of the ball (depending on it's material) continues to change it's form throughout it's trajectory causing it to suddenly change directions. To make the analysis more complete, we must analyze the ball's weight distribution and material complexion. This analysis would emphasize the extra material that is needed to create the air valve. We must also take into consideration the surface of the volleyball, the angle to which the ball contacts the ball, and the air pressure on the inside of the ball. A common instruction in the volleyball world about contacting the ball during a float serve is to aim for the valve in the center of the ball. The valve may only serve it's purpose as a target or it may add to the new shape of the volleyball by adding air pressure: the air that is compressed between the palm of the hand and the valve may force it's way into the ball. Conclusion?? Would the minds of you physicists out there think it necessary to include any more factors into the explanation behind this serve's odd trajectory?