The baseball stitches are replaced for the tennis ball with a fuzzy cover made from a combination of wool and synthetic fiber, often nylon. In this case, the fuzzy cover has two reasons. First, a rubber ball is slippery. Secondly, the fuzzy cover will capture the boundary layer of air that will maximize the Magnus effect during the flight of the tennis ball. Compared with baseball that is pitched with a sidespin, the tennis ball is hit with topspin (forward spin) or backspin (under spin). This is made possible by sliding the racket across the ball in special ways.
Topspin: the top of the ball is moving in the same direction that the entire ball is moving. The racket starts upward from low, moves up to strike the ball and continues toward the shoulder. The topspin causes the ball to sink.
Backspin: the top of the ball is moving in the opposite direction than the tennis ball flight direction. The racket is held high and is brought down to hit the ball. The backspin causes the ball to rise in flight.
In the following video you will learn more about the effect fuzzy surface of a tennis ball has in flight .
Back to Aerodynamics in Sports