The Demonstration

To demonstrate this physical phenomena I shot baseballs from a pitching machine to a catcher, and changed the axis of rotation to demonstrate how the Magnus force caused the ball to curve.

The reason behind the 2 oz. foam balls instead of an official 5 oz. baseball is because they are more practical for a class room demonstration. In addition, with the force acting on a less massive ball the effect is exaggerated.

I would expect that for the effect of the Magnus force to be clearly demonstrated the ball should be projected a distance of at least 15 meters. Ideally, I the effect should be shown at a distance of 56' corresponding to the distance from the pitcher's release point to home plate.

The criteria I wanted my pitching machine to meet were: I want it to be able to pitch a 2 oz. foam ball at speeds upwards of 80 km/h, be light enough that it can be easily transported by one person, it must inflict a spin rate of approximately 1500 rpm, and it must be able to rotate 360^◦ so that I can control the axis of rotation of the pitch.

I chose the ATEC ‘Hitting Streak’ it weighs 25 lbs, can pitch up to 96 km/h, can change angles, and requires a 110 volt electrical source.

The balls I have chosen are SFT (safety foam training) seamed baseballs. The balls have 9” circumference like that of a baseball and weigh 2 oz.