# 11.3.4: Speed of Sound in Solids

The situation with solids is considerably more complicated, with different speeds in different directions, in different kinds of geometries, and differences between transverse and longitudinal waves. Nevertheless, the speed of sound in solids is larger than in liquids and definitely larger than in gases. Young's Modulus for a representative value for the bulk modulus for steel is 160 \(10^9\) N /\(m^2\). A list of materials with their typical velocity can be found in the above book. Speed of sound in solid of steel, using a general tabulated value for the bulk modulus, gives a sound speed for structural steel of

\[

\nonumber

c = \sqrt{ E \over \rho} =

\sqrt{160 \times 10^{9} N/m^{2} \over 7860 Kg /m^3} =

4512 m/s \tag{19}

\]

Compared to one tabulated value the example values for stainless steel lays between the speed for longitudinal and transverse waves.

### Contributors

Dr. Genick Bar-Meir. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or later or Potto license.