Sound Velocity

The speed of sound in air is around 768 mi/hr (1,125 ft/sec, 343m/sec), or about 5 seconds per mile, or 3 seconds per kilometer. That is the reason for the rule of thumb where when you see a flash of lightning, count the number of seconds until you hear the thunder clap, then divide by five. That gives you the approximate distance (in miles) away of the lightning. Divide by three for kilometers.
The speed of sound in any medium is dependent upon the coefficient of stiffness (modulus of bulk elasticity for gas mediums). Density and/or compressibility alone does not determine the speed of sound.

  • Vl  = Velocity of plane longitudinal wave in bulk material.
  • Vs = Velocity of plane transverse (shear) wave.
  • Vext = Velocity of longitudinal wave (extensional wave) in thin rods.
Solids
Substance Density Vl Vs Vext
(g/cm3) (m/s) (m/s) (m/s)
Metals
Aluminum, rolled 2.7 6420 3040 5000
Berylium 1.87 12890 8880 12870
Brass (70 Cu, 30 Zn) 8.6 4700 2110 3480
Copper, annealed 8.93 4760 2325 3810
Copper, rolled 8.93 5010 2270 3750
Gold, hard-drawn 19.7 3240 1200 2030
Iron, Armco 7.85 5960 3240 5200
Lead, annealed 11.4 2160 700 1190
Lead, rolled 11.4 1960 690 1210
Molybdenum 10.1 6250 3350 5400
Monel metal 8.9 5350 2720 4400
Nickel (unmagnetized) 8.85 5480 2990 4800
Nickel 8.9 6040 3000 4900
Platinum 21.4 3260 1730 2800
Silver 10.4 3650 1610 2680
Steel, mild 7.85 5960 3235 5200
Steel, 347 Stainless 7.9 5790 3100 5000
Tin, rolled 7.3 3320 1670 2730
Titaninum 4.5 6070 3125 5080
Tungsten, annealed 19.3 5220 2890 4620
Tungsten Carbide 13.8 6655 3980 6220
Zinc, rolled 7.1 4210 2440 3850
Various
Fused silica 2.2 5968 3764 5760
Glass, pyrex 2.32 5640 3280 5170
Glass, heavy silicate flint 3.88 3980 2380 3720
Lucite 1.18 2680 1100 1840
Nylon 6-6 1.11 2620 1070 1800
Polyethylene 0.9 1950 540 920
Polystyrene 1.06 2350 1120 2240
Rubber, butyl 1.07 1830
Rubber, gum 0.95 1550
Rubber neoprene 1.33 1600
Brick 1.8 3650
Clay rock 2.2 3480
Cork 0.25 500
Marble 2.6 3810
Paraffin 0.9 1300
Tallow 390
Woods
Ash, along the fiber 4670
Beech, along the fiber 3340
Elm, along the fiber 4120
Maple, along the fiber 4110
Oak, along the fiber 3850
Human Body Tissues
Soft Tissue

test

test ddf

dasar

Liquids
Substance Formula Density Velocity at 25°C -δv/δt
(g/cm3) (m/s) (m/sec °C)
Acetone C3H60 0.79 1174 4.5
Benzene C6H6 0.87 1295 4.65
Carbon tetrachloride CCl4 1.595 926 2.7
Castor oil C11H10O10 0.969 1477 3.6
Chloroform CHCl3 1.49 987 3.4
Ethanol amide C2H7NO 1.018 1724 3.4
Ethyl ether C4H10O 0.713 985 4.87
Ethylene glycol C2H6O2 1.113 1658 2.1
Glycerol C3H8O3 1.26 1904 2.2
Kerosene 0.81 1324 3.6
Mercury Hg 13.5 1450
Methanol CH4O 0.791 1103 3.2
Turpentine 0.88 1255
Water (distilled) H2O 0.998 1496.7 -2.4