In Virginia: Anthem Health Plans of Virginia, Inc. trades as Anthem Blue Cross and Blue Shield in Virginia, and its service area is all of Virginia except for the City of Fairfax, the Town of Vienna, and the area east of State Route 123.
For example, at sea level in a standard atmosphere, at a temperaturâ¦e of 59-degrees Fahrenheit (15 Celsius), sound travels 761 miles per hour (1,225 km/p/h). At a temperature of 32-degrees Fahrenheit (0 Celsius) the speed of sound drops to 742 mph (1,194 km/p/h).
The actual speed of sound varies depending on the altitude above sea level because sound travels at slightly different speeds at different temperatures and the temperature varies according to altitude. At sea level, the speed of sound is about 761 miles per hour (1,225 kilometers per hour). At 20,000 feet (6,096 meters), the speed of sound is 660 miles per hour (1,062 kilometers per hour). The speed of sound is commonly refered to as Mach 1, named after the 19th century Austrian physicist Ernst Mach [for biographical details click here].