Compare the spacing of streamlines around a tossed baseball that doesn’t spin in flight with the spacing of streamlines around one that does. Why does the spinning baseball veer from the course of a nonspinning one?
Solution 48E For a non-spinning baseball, the streamlines on either side of the ball will remain the same. When the ball is spinning, the speed of air on one side of the ball will be more. Applying the continuity equation, Av = constant where A = cross section and v = speed, when there is an increase in speed of air, there will be decrease in the air cross-section. This reduced air cross-section will cause a decrease in the spacing of streamlines.