"Frisbee" is brand name by Wham-O for their flying disc. Other companies such as Discraft and DareDevil also make flying discs.
A flying disc is a flat round object with a thick rim. The rim make the disc easier to grip and throw, and also keeps the disc from turning over as it flies. Detailed throwing instructions are below, but the basic goal is to throw the disc while also making the disc spin.
Also mentioned below is a flying ring, made under the brand name Aerobie. Although these designs are very different, they both use air resistance in the same way to fly.
Unlike the Aerobie, flying discs are used in both Ultimate Frisbee and Disc Golf. The Frisbee brand of flying disc is rarely used in official competition in either game, which is why the team sport of Ultimate Frisbee is officially called simply "Ultimate." Still, as "Kleenex" was once a word used to mean "facial tissue," "Frisbee" is still broadly used as a synonym for a flying disc.
The Aerobie Superdisk is an alternative design of flying disc that, although somewhat differently shaped, still has very similar properties to the conventional disc. It has less air resistance. Because there is less resistance to motion, the Aerobie discs can fly farther than the conventional disc. The Aerobie flying ring has minimal drag and holds the world record for the longest flight by a human-thrown projectile. However, due to the lack of a rim, the Aerobie is less suited to angled, curved flights and air-bouncing.
The spin of the disc helps to keep the disc stable in flight and prevent unplanned tilting. This is because a large angular momentum stabilises the disc in the same way that it keeps a gyroscope steady, with the angular force forcing the mass of the disc away from the centre of mass, perpendicular to the axis of rotation. Any unequal force acting on a particular area of the disc is quickly redirected to be equal over the circumference of the disc. As the disc spins faster, it becomes more stable due to the rapidity of the equalisation of forces.
The force required to accelerate the disc is directly proportional to the mass of the disc. This decreases the acceleration of the disc, assuming that the force of projection is constant. Therefore, discs come in a variety of weights, although those used for Ultimate are mainly 175 g in mass, heavier than the majority of discs and considerably heavier than an aerobie.
Flying discs (including Frisbees) can be thrown in many ways. All involve spinning the disc to give it gyroscopic stability, and accelerating its mass to a certain velocity. Without spin, a disc will wobble and fall; without velocity, the disc will not go anywhere. Using these two guidelines, any number of throws are possible. Most discs are designed to create lift when thrown with the flat side up.
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Flying discs (commonly called Frisbees) are disc-shaped objects, which are generally plastic and roughly 20 to 25 centimeters (8–10 inches) in diameter, with a lip. The shape of the disc, an airfoil in cross-section, allows it to fly by generating lift as it moves through the air while rotating. The name Frisbee is a registered trademark of the Wham-O toy company, but is often used generically to describe all flying discs.
Flying discs are thrown and caught for recreation, and as part of many different flying disc games. 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. Disc dog sports use relatively slow flying discs made of more pliable material to better resist a dog's bite and prevent injury to the dog. Ring shaped discs are also available which typically fly significantly farther than any traditional flying disc. There are illuminated discs meant for night time play that use phosphorescent plastic, or battery powered light emitting diodes. There are also discs that whistle when they reach a certain velocity in flight.
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 were 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.
In 1957, Wham-O co-founder Richard Knerr, decided to stimulate sales by giving the discs the additional brand name "Frisbee" (pronounced the same as "Frisbie"), after hearing that East Coast college students were calling the Pluto Platter by that name. The man who was behind the Frisbee's phenomenal success however was "Steady" Ed Headrick, hired in 1964 as Wham-O's new General Manager and Vice President in charge of marketing. Headrick soon redesigned the Pluto Platter by reworking the rim thickness, and top design, creating a more controllable disc that could be thrown accurately.
Flying disc games are games played with flying discs (sometimes called by the trademarked name Frisbees). Some of the games, such as Ultimate and Disc golf, are sports with substantial international followings.
Disc dog is the more generic name for what is commonly called Frisbee dog. In disc dog competitions, dogs and their human disc throwers compete in events such as distance catching and somewhat choreographed freestyle catching. The sport celebrates the bond between handler and dog, by allowing them to work together. The term "disc" is preferred because "Frisbee" is a trademark (held by Wham-O) for a brand of flying disc.
Disc golf (also known as frisbee golf or "frolf") is a disc game in which individual players throw a flying disc into a basket or at a target. According to the Professional Disc Golf Association, "The object of the game is to traverse a course from beginning to end in the fewest number of throws of the disc." Disc golf is inexpensive and is physically accessible for all ages and athletic ranges and therefore attracts a diverse range of players. A great majority of established disc golf courses are free. The game is played in the United States and more than 20 other countries around the world.
Fricket or disc cricket is a disc game generally played by two teams of two players each (two-on-two), though it is possible to play one-on-one. The game is roughly derived from cricket (though in some ways having more in common with horseshoes), and played with flying discs. Fricket is also sometimes called cups or crispy wickets. The name "fricket" is derived from a combination of the words "Frisbee" (a trademarked flying disc brand name) and "cricket".
Friskee is a sport played with a flying disc, two gates and two teams. One team has to throw the disk through the other team's gate. The person currently holding the disc cannot run until it leaves his hand. There is no arbitrator and everyone is permitted to stop any opposing player in any way. But the gentlemanly spirit of the game must be maintained, so heavy injuries are few.
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