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Unit conversion - stress-wave propagation speed

  1. Aug 16, 2015 #1
    Dear Friends,

    The stress-wave propagation speed is calculated using : sqrt (elastic modulus/density)
    The unit of elastic modulus is GPa, and that of density is gram/cm^dim

    Can anyone please tell me how I can convert the resulting value to m/s (meter/second)?

  2. jcsd
  3. Aug 16, 2015 #2


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    I'm not sure what cm^dim is.

    Any density given in g / cc can also be converted to kg / m3

    Pascals are derived units. Write pascals in terms of basic units and see what's left after dividing by density.
  4. Sep 18, 2015 #3


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    Using these units (GPa and gm/cc) the velocity is in km/s so multiply by 1000
  5. Sep 20, 2015 #4


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    Instead of learning 20 different cases, it is easier to learn how to convert units in general:

    GPa = 109 Pa
    kg = 1000 g
    m = 100 cm, which implies m3 = 1003 cm3
    All those are universal SI prefixes.

    Pa = N/m2

    If you plug in your units, convert them and simplify, you'll naturally get the correct result.
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