Compressibility of water is $5\times {10}^{-10}{\mathrm{m}}^2/\mathrm{N}$. Find the decrease in volume (in mL) of 100 mL of water when subjected to a pressure of 15 MPa.

The compressibility K is the reciprocal of the bulk modulus. K =$\frac{∆P}{{\displaystyle \frac{∆V}{V}}}$

Decrease in volume = $∆v$= $∆p v \frac{1}{k}$

$\begin{array}{c}\therefore \mathrm{\Delta V}=-\mathrm{V\Delta p} compressibility\\ =-\left(100\mathrm{mL}\right)\left(5\times {10}^{-10}{\mathrm{m}}^2/\mathrm{N}\right)\left(15\times {10}^6\mathrm{N}/{\mathrm{m}}^2\right)\\ =-0.75\mathrm{mL}\end{array}$

The decrease in volume is thus 0.75 mL.