Speed of sound conversions
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About speed of sound
The speed of sound is the distance traveled by a sound wave through an elastic medium during a period of time. In dry air at 20 °C (68 °F), the speed of sound is equal to 343.2 meters per second (m/s), the derived unit of speed in the International System of Units (SI).
The speed of sound is also equal to approximately 1,236 kilometers per hour (km/h), or 1,126 feet per second (ft/s), or 768 miles per hour (mph), or approximately one mile in five seconds or about one kilometer in three seconds.
The speed of sound varies depending on the medium the sound wave travels. Specifically, the sound wave travels faster in liquids and non-porous solids than it does in air:
- The speed sound travels through water at 20 °C (68 °F) is about 1,484 m/s (i.e., nearly 4.3 times faster than in dry air at the same temperature)
- The speed sound travels through iron at 20 °C is about 5,120 m/s (i.e., about 15 times faster than in dry air at the same temperature)
Plural: speed of sound