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6 March 2014 1:04 pm ,
Vol. 343 ,
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
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ScienceShot: The Physics of Usain Bolt
25 July 2013 7:15 pm
In the summer of 2009, during the World Championships in Athletics in Berlin, Jamaican sprinter Usain Bolt set a world record time of 9.58 seconds for the 100-meter dash—but he did so with a slight wind at his back. Now, a new analysis suggests that Bolt’s time without the tailwind would still have been a record-setter. Researchers used weather conditions during the race to estimate Bolt’s coefficient of drag, which is related to his body’s wind resistance. That parameter, along with data about the sprinter’s position (collected by lasers every 0.1 second during the race), suggests that Bolt’s time sans wind assistance would have been 9.68 seconds, the researchers report today in the European Journal of Physics. That’s 0.1 seconds slower than the official result but still good enough to squeak past Bolt’s previous world record time of 9.69 seconds, which he had set at the Beijing Olympics the year before. Race data also show that Bolt sprang from the starting blocks with an acceleration of 9.5 meters per second squared—that’s almost 0.97 g, the acceleration due to Earth’s gravity—and was churning out a whopping 2.6 kilowatts of power (3.5 horsepower) less than 1 second later.