Drinking cranberry juice is a fairly well-known and natural way to both help prevent urinary tract infections, as well as help speed the recovery process when a UTI develops. Just drinking two 4-ounce glasses of cranberry juice daily is often enough to both prevent a UTI and speed recovery when an infection does develop.
Ultrasound waves travel faster through a stiff medium, such as bone. In echocardiography, the velocity of sound is assumed to be approximately 1,540 m/sec (or 1.54 m/msec). Sound waves travel through the air with speed of 330 m/s.
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].