Projectile Motion https://en.wikipedia.org/wiki/Projectile_motion http://www.physicsclassroom.com/class/1DKin/Lesson-6/Kinematic-Equations d= displacement t= time Vf= final velocity Vi= initial velocity a= acceleration due to gravity     Projectile Motion describes the motion of the ball. Whether it's a serve, set, or dig, a volleyball will always travel in a parabolic motion. This is because the only force that acts on the ball after the ball is given an initial force is gravity assuming that there is no air resistance. However in an ideal world, the ball will not travel in a perfect parabolic motion due to air resistance. For example a float serve is a serve that puts no spin on ball, and the ball will travel depending on air flow and can float in any direction. This serve is used so that the opponent can not predict where the ball will be at any instance. In this example other principles explain this movement such as Bernoulli's principle. Assuming that there is no air resistance, with some known values, kinematic equations can be used to calculate how far and high the ball will travel.