On the flight of an American Football

In this paper we examine the detailed theory of the American football in flight, with spin and air resistance included. We find the theory has much in common with the theory of a gyroscope and also rocket trajectory with a misaligned thruster. Unfortunately most of the air resistance data, for rocke...

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Bibliographic Details
Published inarXiv.org
Main Authors Horn, Curtis, Fearn, Heidi
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 04.06.2007
Subjects
Ammunition
Ballistic missiles
Ballistics
Drag
Football
Moments of inertia
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Summary:In this paper we examine the detailed theory of the American football in flight, with spin and air resistance included. We find the theory has much in common with the theory of a gyroscope and also rocket trajectory with a misaligned thruster. Unfortunately most of the air resistance data, for rocketry and ballistics, is for speeds of Mach 1 or higher, where the air resistance increases dramatically. We shall approximate a realistic air resistance, at the slower speeds of football flight, with a drag force proportional to cross sectional area and either \(v\) or \(v^2\), depending on speed, where \(v\) is velocity of the football. We begin with a discussion of the motion, giving as much detail as possible without the use of complex analytic calculations. We point out the previous errors made with moments of inertia and make the necessary corrections for more accurate results. We show that the shape of an American football closely resembles a parabola of revolution.
ISSN:2331-8422