Question

The volume change of a solid copper cube $10cm$ on an edge, when subjected to a pressure of $7MPa$ is then
(Bulk modulus of copper $=140GPa$)

• A. $5\times {10}^{-2}{cm}^3$.
• B. $10\times {10}^{-2}{cm}^3$
• C. $15\times {10}^{-2}{cm}^3$
• D. $20\times {10}^{-2}{cm}^3$

Answer 1

Answer: (A)

$5\times {10}^{-2}{cm}^3$.

Here $L=10cm=10\times {10}^{-2}m;P=7MPa=7\times {10}^{6}Pa;B=140GPa=140\times {10}^{9}Pa$
As $B=\frac{P}{\Delta V/V}$
$\therefore \Delta V=\frac{PV}{B}=\frac{P{L}^3}{B}=\frac{(7\times {10}^{6}Pa){(10\times {10}^{-2}m)}^3}{140}=5\times {10}^{-8}{m}^3=5\times {10}^{-2}{cm}^3$