The Fastest Man on Earth.

The news has it that the fastest man in the world is the man who set the record in the 100 meter race. Yesterday at a Grand Prix meet in Doha, Qatar, the new fastest man on earth was Justin Gatlinng who beat the record at an impressive 9.76 seconds. That's an amazing 23 mph (37 km/hour). The last record was 9.77 seconds (Asafa Powell, from Jamaica on June 14, 2005) and the figure was 10.6 seconds in 1912.

Here's a graph of the evolution of the World record in the last century:
Yet it seems that the idea of using the 100 meter race record is wrong. The fastest man on the planet may actually be a 200 meter runner. The reason? Velocity.

Achieving this maximum velocity will take athletes in both events approximately 35-40 metres and the 200m by the nature of the distance will spend longer at peak velocity than the 100m runner. Therefore the average running velocity is higher in a 200m runner as they will run for approximately 160m at peak velocity compared to a 100m runner who will run for only around 60m at the same rate. (source here)

So as a result the fastest man on earth may be Michael Johnson with his 200m world record of 19.32 - which he set in 1996 and which has yet to be beaten. It equates to 9.66 for each 100 metres which is significantly quicker. The man was running at 28mph (45 km/h). (see here, and here)