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Janibekov Effect
The tennis racket theorem or intermediate axis theorem, is a kinetic phenomenon of classical mechanics which describes the movement of a rigid body with three distinct principal moments of inertia. It has also been dubbed the Dzhanibekov effect, after Soviet cosmonaut Vladimir Dzhanibekov, who noticed one of the theorem's logical consequences whilst in space in 1985. The effect was known for at least 150 years prior, having been described by Louis Poinsot in 1834 and included in standard physics textbooks such as ''Classical Mechanics'' by Herbert Goldstein throughout the 20th century. The theorem describes the following effect: rotation of an object around its first and third principal axes is stable, whereas rotation around its second principal axis (or intermediate axis) is not. This can be demonstrated by the following experiment: Hold a tennis racket at its handle, with its face being horizontal, and throw it in the air such that it performs a full rotation around its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennis Racquet Principal Axes
Tennis is a List of racket sports, racket sport that is played either individually against a single opponent (singles (tennis), singles) or between two teams of two players each (doubles (tennis), doubles). Each player uses a tennis racket strung with a cord to strike a hollow rubber tennis ball, ball covered with felt over or around a net and into the opponent's tennis court, court. The object is to manoeuvre the ball in such a way that the opponent is not able to play a valid return. If a player is unable to return the ball successfully, the opponent scores a Point (tennis), point. Playable at all levels of society and at all ages, tennis can be played by anyone who can hold a racket, including Wheelchair tennis, wheelchair users. The original forms of tennis developed in France during the late Middle Ages. The modern form of tennis originated in Birmingham, England, in the late 19th century as lawn tennis. It had close connections to various field (lawn) games such as croqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
