AY Honors/Ultimate Disc/Answer Key

A Wham-O Professional Frisbee

Flying discs (commonly called Frisbees) are the general name for any number of discs which are generally plastic, roughly 20 to 25 centimeters (8–10 inches) in diameter, with a lip. They are designed to fly aerodynamically when thrown with rotation and can be caught by hand. The name Frisbee is a registered trademark of the Wham-O toy company, but the term is often used generically to describe all versions of the flying disc.

A wide range of flying disc variants are available commercially. Disc golf discs are usually smaller but denser and are tailored for particular flight profiles to increase/decrease stability and distance. When it was discovered that dogs enjoyed chasing and retrieving the slow-moving discs, special discs were designed with more pliable material that would better resist a dog's bite, and prevent possible injury that may occur with more rigid materials. Disc dog competitions, in which dogs' disc-catching skills are judged, have become quite popular as well. Ring-like discs shaped like a Saturn's ring, known as Aerobies, typically fly significantly farther than any traditional flying disc. The evolution has continued with the advancement of lighting a flying disc for evening and night-time play. By using a Flashflight disc, players can extend the throw and catch playing time after the sun goes down.

History

People have been throwing cake pans, pie tins, cookie jar lids, and other such objects for centuries. The earliest known disc object to be thrown around was the chakram, which was used as a weapon in ancient India. In later times, flying discs were used for recreational purposes. The clay target used in trapshooting is almost identical to a flying disc in shape, but was designed in the 19th century. The modern day flying discs, however, began when people started making them out of plastic, and modern flying discs are developed from the "Flyin'-Saucer", originally invented by Fred Morrison and co-developed and financed by Warren Franscioni in 1948. However, that initial disc was largely unsuccessful. A later model made by Morrison in 1955 and sold as the "Pluto Platter" was bought by Wham-O on January 23, 1957. In the next year, Wham-O renamed the toy "Frisbee", a (probably deliberate) misspelling of the name of the Frisbie Pie Company of Bridgeport, Connecticut.

Games using flying discs

• Ultimate
• Freestyle frisbee
• Disc Golf - the traditional game of Golf played with flying discs (frisbees) instead of clubs and balls.
• Durango Boot
• Double Disc Court
• Guts Frisbee
• Flutterguts
• Friskee
• Disc dog
• Dodge Frisbee
• Goaltimate
• Schtick
• Fricket, (sometimes called Cups, Suzy Sticks, Frisnok or Disc Cricket)
• Hot Box
• Fris-Nok, the traditional Icelandic-Canadian game.

Physics

Lift is generated in primarily the same way as a traditional asymmetric airfoil, that is, by accelerating upper airflow such that a pressure difference gives rise to a lifting force. Small ridges near the leading edge act as turbulators, reducing flow separation by forcing the airflow to become turbulent after it passes over the ridges.

The rotating flying disc has a vertical angular momentum vector, stabilizing its attitude gyroscopically. Depending on the cross-sectional shape of the airfoil, the amount of lift generated by the front and back parts of the disc may be unequal. If the disc was not spinning, this would tend to make it pitch. When the disc is spinning, however, such a torque would cause it to precess about the roll axis, causing its trajectory to curve to the left or the right. Most discs are designed to be aerodynamically stable, so that this roll is self-correcting for a fairly broad range of velocities and rates of spin. However, many disc golf discs are intentionally designed to be unstable. Higher rates of spin lead to better stability, and for a given rate of spin, there is generally a range of velocities that are stable.

Even a slight deformation in a disc, called a "Taco," as extreme cases look like a taco shell, can cause adverse affects when throwing long range. It can be observed by holding the disc horizontally at eye level and looking at the rim while slowly rotating the disc.

Trivia

• In the animated motion picture The Secret of NIMH, based on the book Mrs. Frisby and the Rats of NIMH, the main character's name was changed in post-production from "Frisby" to "Brisby" to avoid potential trademark infringements.
• In the film Back to the Future Part III, Marty McFly throws a metal pie dish at a gunman in order to save Doc Brown's life. He notices the dish is stamped "Frisbie Pie Company", giving a fictional origin to the current use of the term.
• Richard Feynman in his book Surely You're Joking, Mr. Feynman! suggests that watching the wobble of a plate tossed in the Cornell University cafeteria stimulated him to develop mathematics that eventually led to his Nobel prize winning work in quantum electrodynamics [1].

See also

• Aerobie
• Disc throws
• Frisbeetarianism
• Chakram

Further reading

• Frisbee, A Practitioner's Manual and Definitive Treatise Stancil E.D. Johnson, M.D. Workman Publishing Company, New York (July, 1975) ISBN 0-911104-53-4
• The Official Frisbee Handbook Goldy Norton, Bantam Books, Toronto/New York/London (July, 1972) no ISBN
• Frisbee Players' Handbook Mark Danna, Dan Poynter, Parachuting Publications, Santa Barbara, California (1978) ISBN 0-01-551619-5
• Frisbee Sports & Games Charles Tips, Dan Roddick, Celestial Arts, Millbrae, California (March 1979) ISBN 0-89087-233-3
• Frisbee by the Masters Charles Tips, Celestial Arts, Millbrae, California (March 1977) ISBN 0-89087-142-6
• Spinning Flight : Dynamics of Frisbees, Boomerangs, Samaras and Skipping Stones, Ralph Lorenz, Copernicus New York, September 2006 ISBN 0-387-30779-6

External links

• Frisbee, about.com
• Ultimate Players Association sports governing body of Ultimate in the USA
• World Flying Disc Federation international sports governing body for all
• Discraft manufacturer of flying discs for Ultimate, Disc Golf, and Freestyle
• Wham-O Frisbee disc website manufacturer of Frisbee brand flying discs
• Flashflight disc website manufacturer of Light-up flying discs
• UK Ultimate Association
• frisbeecollective.com