Speed of Sound
    The speed of sound depends on the type of medium that the wave is traveling through.  In air, the speed of sound is about 340 m/s or 760 mph for a normal spring day.  The speed also depends on the temperature of the medium.
The formula used to figure out the speed of sound, in air, on any given day is;  
v = 331 m/s + 0.6T  
where v is the velocity of the wave, T is the temperature of the air in degrees celcius, 331 m/s is the speed of sound at 0°C, and 0.6 is just a constant.  So as the temperature increases, so does the speed of sound at a rate of 0.6 m/s for each celcius degree.
The following table represents the speed of sound in various media. It was taken from Gundersen's
 The Handy Physics Answer Book
Medium          
Speed of sound (m/s)
Air (0°)
 331
Air (20°)
 343
Air (100°)
 366
Helium (0°)
 965
Mercury
 1452
Water (20°)
 1482
Lead
 1960
Wood (Oak)
 3850
Iron
 5000
Copper
 5010
Glass
 5640
Steel
 5960
  
The speed of sound also depends on the compressiblility and inertia of a material.  
This can be represented as :  v2 = (elastic property / inertial property). Where the elastic property is usually the bulk modulus or Young's modulus of the medium, and the inertial property is the density of the medium.


BACK    HOME    NEXT