During 12th IAAF World Championships in Athletics Berlin 2009 jamaican sprinter Usain Bolt broke his own record in 100 meters race. He ran 100m final race in 9.58s, that gives average speed 10.4384 m/s (23.35mph) (click on the links to convert speed to other units).
The previous world record was held during Olympic Games Beijing 2008 . Usain Bolt ran 100 meters in 9.69s. Average speed in this race was 10.3199 m/s (23.085mph)
100 meters final results:
Usain Bolt 9.58s !!!! New World Record, Tyson Gay 9.71s, Asafa Powell 9.84s