As of 20 August 2008, Usain Bolt is the the world's fastest man with a 200 meter sprint of 19.30 seconds, giving an average speed of 10.36 meters per second. There are 1609.344 meters in a mile, so 10.36 m/s / 1609.344 m/mi = 0.0064374 miles/second. There are 3600 seconds in an hour, so 0.0064374 mi/s * 3600 s/hr = 23.175 miles/hour. Usain Bolt clocked an *average* speed of 23.175 mph during his world record run, however he may have achieved speeds of 23-27 mph in the early part of the sprint.
The U.S. is growing, and the world is growing faster. (Andreas Kermann/iStockphoto) The U.S. entered 2016 with an estimated population of 322,762,018 according to an end-of-year estimate from the U.S. Census Bureau, meaning that we added more than 2.4 million people to the population over the course of the year.
US Population to Hit 324 Million in 2016, 400 Million in 2050. The U.S. population is aging, and is moving away from one which is largely descended from people who came from Europe and more toward people from Central America, Mexico, and Asia. And, the rate at which the U.S population is growing has stagnated. There will be 323,996,000 Americans in 2016, barely up from 321,369,000 last year and slightly less than 326,626,000 in 2017. The U.S. population will not reach over 400,000,000 until 2051, when the Census forecasts it will reach 400,124,000.