The bulk modulus of a substance measures the substance's resistance to uniform compression. It is defined as the ratio of the infinitesimal pressure increase to the resulting relative decrease of the volume.
Applicable units are those of quantitykind:BulkModulus
http://en.wikipedia.org/wiki/Bulk_modulus
The bulk modulus of a substance measures the substance's resistance to uniform compression. It is defined as the ratio of the infinitesimal pressure increase to the resulting relative decrease of the volume.
$K = \frac{p}{\vartheta}$, where $p$ is pressure and $\vartheta$ is volume strain.
http://www.iso.org/iso/catalogue_detail?csnumber=31889