Using this difference, one can estimate how far away the bolt of lightning is by timing the interval between seeing the flash and hearing thunder. The speed of sound in dry air is approximately 343 m/s or 1,127 ft/s or 768 mph (1,236 km/h) at 20 Â°C (68 Â°F).
From Wikipedia, the free encyclopedia. Fort Pierce is a city in and the county seat of St. Lucie County, Florida, United States. It is also known as the Sunrise City, sister to San Francisco, California, the Sunset City. The population was 41,590 at the 2010 census. As of 2012, the population recorded by the U.S. Census Bureau was 42,645.
Trappers with Indian wives had moved to the area in the 1830s and settlers in the 1850s. Washington's first telegraph line paralleled Military Road that ran through the heart of Edgewood. Approximately 420 Americans (apart from Indians) resided in what is now Pierce County in 1858. By 1862, 681 non-Native Americans were reported to be residents of Pierce County. Evidence indicates that the first building on the North Hill (Surprise Lake) was a one-room log building formed as School District 27 in 1891.