Bolt, faster than bullet!


Scientists have revealed that Olympic champion Usain Bolt produced 50 times more energy than that of a speeding bullet during one of his record-breaking 100metre runs. Physicists studying the secrets of Bolt’s success announced the findings after a detailed study of the Jamaican sprinter’s 100m performance during the 2009 World Championships in Berlin.
They discovered that he produced a remarkable 81.58 kilojoules (kJ) of energy, compared to just 1.6 kJ of energy a bullet produces when it leaves the barrel of a 0.44 calibre Magnum handgun. They also calculated that he reached a top speed of 27 miles per hour (mph) during the race. But unlike a bullet, which can reach 1,000mph, Bolt’s huge 6ft 5inches frame meant more than 92 per cent of his energy was absorbed in battling air resistance. The researchers found he had to produce an ‘extraordinary’ amount of power to reach his 100m world record time and because he is so tall he is less aerodynamic than the average human. They made the discovery after taking into account the altitude of the Berlin track, the temperature at the time of the race and the cross-section of Bolt himself.
Bolt reached a maximum power of 2,619.5 watts, a horsepower of 3.5, within 0.89 seconds when he was only at half his maximum speed, which shows the effect the drag had on his acceleration. Jorge Hernandez, co-author of the study which was published in the European Journal of Physics said, “Our calculated drag coefficient highlights the outstanding ability of Bolt. He has been able to break several records despite not being as aerodynamic as a human can be. The enormous amount of work that Bolt developed in 2009, and the amount that was absorbed by drag, is truly extraordinary.” He remarked that it is very hard to break records nowadays, even by hundredths of a second, as the runners must act very powerfully against a tremendous force which increases massively with each bit of additional speed they are able to develop. “This is all because of the ‘physical barrier’ imposed by the conditions on Earth. Of course, if Bolt were to run on a planet with a much less dense atmosphere, he could achieve records of fantastic proportions,” he noted.
The researchers, from the National Autonomous University of Mexico, claim their equations can be used to calculate the effect of a tailwind, which can vary between races and significantly reduce running times. They compared Bolt’s time in Berlin with his previous world record time of 9.69 seconds, set during the Beijing Olympics a year earlier. In Beijing Bolt was running with no tailwind, but in Berlin there was a tailwind of 0.9 metres per second. According to the researchers’ new equations, Bolt would have clocked a slower time in Berlin if there was no tailwind, but would still have beaten his world record from Beijing – they predict that he would have run a time of 9.68 seconds. The calculations in the study were tested for accuracy by fitting real-life experimental data into the equations. The figures were from the International Association of Athletics Federation’s (IAAF) laser velocity guard device, which recorded Bolt’s position and speed every one-tenth of a second during the 2009 race in Berlin. Dr Hernandez added, “The accurate recording of Bolt’s position and speed during the race provided a splendid opportunity for us to study the effects of drag on a sprinter. If more data become available in the future, it would be interesting to see what distinguishes one athlete from another.”


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