Usain Bolt: Faster than a bullet - over 100 metres...
FASTER THAN A BULLET – OVER 100 METRES . . .
He may not be quite as fast as a speeding bullet, but Usain Bolt certainly produces more energy than one.
Physicists have calculated that the world's fastest man produced 50 times more energy during his record-breaking 100m sprint than a bullet as it leaves the barrel of a 0.44 calibre Magnum handgun.
They worked out that the runner achieved a top speed of 27mph during his 9.58-second sprint at the 2009 World Championships in Berlin.
However, the large amount of wind drag created by his 6ft 5ins frame limited how fast he could go. Computer models found that less than 8pc of the mechanical energy he produced was used for movement, while the rest was spent fighting the drag.
Jorge Hernandez Gomez, the lead author of the study from the National Autonomous University of Mexico, said: "It is so 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."
The researchers, whose findings are published in the European Journal of Physics, calculated that Bolt produced 81.58 kilojoules of kinetic energy during the record-breaking race. (© Daily Telegraph, London)