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:''Not to be confused with reverse bungee.'' Bungee jumping (; also spelt "Bungy" jumping, which is the usual spelling in New Zealand and several other countries)〔AJ Hackett (2008) (''Welcome to Cairns'' ). Retrieved on 17 October 2008.〕〔Jungle Bungy Jump (2008). (''Phuket Thailand'' ). Retrieved on 17 October 2008.〕 is an activity that involves jumping from a tall structure while connected to a large elastic cord. The tall structure is usually a fixed object, such as a building, bridge or crane; but it is also possible to jump from a movable object, such as a hot-air-balloon or helicopter, that has the ability to hover above the ground. The thrill comes from the free-falling and the rebound.〔Kockelman JW, Hubbard M. Bungee jumping cord design using a simple model. ''Sports Engineering'' 2004; 7(2):89-96〕 When the person jumps, the cord stretches and the jumper flies upwards again as the cord recoils, and continues to oscillate up and down until all the kinetic energy is dissipated. == History == The first modern bungee jumps were made on 1 April 1979 from the Clifton Suspension Bridge in Bristol, by David Kirke and Simon Keeling, both members of the Oxford University Dangerous Sports Club.〔Aerial Extreme Sports (2008). (''History of Bungee'' ). Retrieved on 17 October 2008.〕 The jumpers were arrested shortly after, but continued with jumps in the US from the Golden Gate Bridge and the Royal Gorge Bridge (this last jump sponsored by and televised on the American programme ''That's Incredible''), spreading the concept worldwide. By 1982, they were jumping from mobile cranes and hot air balloons. Organised commercial bungee jumping began with the New Zealander, A J Hackett, who made his first jump from Auckland's Greenhithe Bridge in 1986. During the following years, Hackett performed a number of jumps from bridges and other structures (including the Eiffel Tower), building public interest in the sport, and opening the world's first permanent commercial bungee site, the Kawarau Bridge Bungy at the Kawarau Gorge Suspension Bridge near Queenstown in the South Island of New Zealand. Hackett remains one of the largest commercial operators, with concerns in several countries. Several million successful jumps have taken place since 1980. This safety record is attributable to bungee operators rigorously conforming to standards and guidelines governing jumps, such as double checking calculations and fittings for every jump. As with any sport, injuries can still occur (see below), and there have been fatalities. A relatively common mistake in fatality cases is to use a cord that is too long. The cord should be substantially shorter than the height of the jumping platform to allow it room to stretch. When the cord becomes taut and then is stretched, the tension in the cord progressively increases. Initially the tension is less than the jumper's weight and the jumper continues to accelerate downwards. At some point, the tension equals the jumper's weight and the acceleration is temporarily zero. With further stretching, the jumper has an increasing upward acceleration and at some point has zero vertical velocity before recoiling upward. See also Potential energy for a discussion of the spring constant and the force required to distort bungee cords and other spring-like objects. The Bloukrans River Bridge was the first bridge to be 'bungee jumped off' in Africa when Face Adrenalin introduced bungee jumping to the African continent in 1990. Bloukrans Bridge Bungy has been operated commercially by Face Adrenalin since 1997, and is the highest commercial bridge bungy in the world.〔(My Destination Website ), retrieved 26 April 2012〕 In April 2008 a 37-year-old Durban man, Carl Mosca Dionisio, made bungee jumping history when he jumped off a 30 m (100 ft) tower attached to a bungee cord made entirely of 18,500 condoms.〔http://newsflavor.com/alternative/condom-bungee-jump/〕 〔http://www.metro.co.uk/news/world/143942-bungee-jumper-uses-30m-condom-rope〕 〔http://www.lady-arlete.com/bungy.html〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「bungee jumping」の詳細全文を読む スポンサード リンク
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