Because as an international event not driven by American oddities of measurement, the more common meter is used. There is a 100 meter dash, and the reigning Medalists are for the 2008 Olympics:
Women
The 100 yard dash is not run in the Olympics but the 100 meter dash is. Frank Jarvis of the United States won gold with a time of 11.0 seconds in the final. He also ran a 10.8 second preliminary heat which tied the world record at the time.
Roman Cress competed in the 100 meter dash at the 2008 Beijing Olympics and is an education administrator at North View Junior High School in Brooklyn Park, Minnesota
Bob Hayes has the world record in the 100 yard dash. This record was set in the year 1963. This is a separate race from the 100 meter dash.
11.6 in 100 meters is 4.2 (4.242816) seconds in the 40-yard dash.
50 yard dash, 100 yard dash, pole vault, etc
A 10.2 is faster.
A reliable way to convert a hand-held 100-yard time to an electronic 100-meter time is to multiply the hh-time by 1.103. Therefore, 10.2 in the 100-yard dash time equates to an 11.25 100-meter dash time. Also, to convert an electronic 100-yard dash time to an electronic 100-meter dash time, multiply the first time by 1.088. For example, a 10.20 electronic 100-yard time equates to an 11.10 electronic 100-meter dash time.
10.7 100 meter dash = 9.78 100 yards
4.0 (4.0672512) seconds in the 40-yard dash.
A 12.5-second 100m equates to a time of 4.572 seconds in the 40-yard dash.
Run in your lane
4.28