 如何測算“搶跑”
[ 2008-08-25 16:54 ]
根據(jù)國際田聯(lián)比賽規(guī)則，正常的起跑必須是裁判員的起跑信號發(fā)出后運動員的方可起跑。如果在起跑信號發(fā)出之前，參賽運動員便開始起跑，即為搶跑。所有人員必須重新回到原點，等到裁判員發(fā)出起跑信號后方可起跑，現(xiàn)在國際田聯(lián)規(guī)定在比賽中同一組的運動員在起跑時只能搶跑一次，當?shù)诙螣o論是哪個人出現(xiàn)搶跑情況時，當場罰出。那么，賽場上是如何來測算“搶跑”呢？下面就讓我們一起來了解一下吧。
Research has found that a reaction time faster than one-tenth of a second is impossible for a human, and the runner is therefore deemed to have anticipated the gun. Under current international rules, a sprinter is allowed one false start without penalty; the second false start（搶跑） results in disqualification. A proposed rule change would institute a "zero-tolerance" policy that would disqualify a sprinter（賽跑選手）after the first false start.
The most common way to detect a false start in major track meets is by a device called ReacTime. The ReacTime unit sits on the back of the starting block. It is connected either by wires or by radio signals to a main computer near the race starter (usually an individual with a starting gun). The device measures the pressure that an athlete exerts on the starting block when in a set position and relays this information in real-time to the main computer, measured down to one-thousandth of a second.
When the starting gun is fired, the main computer marks the exact moment of the start, and also calculates the time it will be one-tenth of a second later. Each pressure-sensitive unit continues to relay information back to the main computer as the runners leave their respective starting blocks and begin down the track.
As the runners leave the blocks, the pressure exerted on the blocks increases and then decreases; on a graph, this rise and fall of pressure forms a parabola. The computer analyzes the data for each runner and determines the exact moment when the pressure begins to increase at a certain rate. This is the split-second at which the runner reacted.
If this split-second precedes the exact start time, a false start has occurred. If the computer detects that the runner's reaction time was less than the one-tenth of a second allowed under IAAF guidelines, this is also a false start. In either case, a signal is relayed to the starter via a small earpiece. It is then the starter's responsibility to fire the gun again, signifying a false start and bringing the runners back to the starting blocks. The starter then verifies that the equipment worked properly, determines which runner committed the false start, informs the runner and then gets the runners back in place to try again.
（來源：howstuffwork 實習(xí)生吳昭文 英語點津 Annabel 編輯）
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