Motion Analysis of the 2009 Men’s 100 m World Record

Abstract

The fabulous 100 m world record of Jamaica’s Usain Bolt (9.58 s on Aug. 16^th, 2009, in Berlin) has intrigued not only sports fans. It can also be fruitfully used in physics teaching as a real life event, although there are some caveats.

After downloading public-domain, high-resolution renditions of the record race for a motion analysis, we first used video-cutting software to clock individual frames when the winning athlete passed the ten 10 visible on-track markers. A polynomial fit of these data was possible with r² = 0.9998, however, it failed to produce physically plausible velocities and accelerations.

Data published by the IAAF, when evaluated in the same way, did not produce these artifacts, and showed the record-breaking dash to be composed of a 3-second phase with decreasing acceleration, followed by a high-speed phase peaking at 44,2 km/h near 7,5 s. A slight deceleration at the very end can be used as an estimate for still further improvements of the 100 m world record, as had been down before.¹ The relevance of the results w.r. to biokinematics as well as training methods are discussed.

¹H.K. Eriksen et al., Am. J. Phys 77, 324 (2009)