During his 100 m world record run in Berlin in 2009, what top speed did Usain Bolt reach, in kilometres per hour?

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Answer

About 45 km/h

He covered the 100 metres in just 41 strides, while most of his rivals needed around 44 or 45.

How to estimate it

Bolt ran 100 m in 9.58 seconds, an average of 100 / 9.58 = 10.4 m/s. But he started from a standstill and needed about 60 m to reach full speed, so his peak was roughly 20 percent above the average: 10.4 × 1.2 = 12.5 m/s. Multiply by 3.6 to convert: 45 km/h. Timing data from Berlin show a peak of about 45 km/h.

Source: World Athletics; Journal of Experimental Biology

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