Physics - Elasticity Question with Solution | TestHub

Bulk modulus $K$ is defined as the ratio of hydrostatic stress (pressure) to volumetric strain. Volumetric strain is given by $\frac{\Delta V}{V}=\frac{V_0}{V}$. Therefore, $$K=\frac{\text{Stress}}{\text{Volumetric Strain}}=\frac{P}{V_0/V}=\frac{PV}{V_0}$$