$A$ solid sphere of radius $10\,cm$ is subjected to a pressure of $5\times 10^8\,Nm^{-2}$. Determine the change in its volume. The bulk modulus of the material of the sphere is $3.14 \times 10^{11}\,Nm^{-2}$.

The formula for bulk modulus $B$ is given by $B = \frac{P}{\Delta V / V}$,where $P$ is the pressure,$\Delta V$ is the change in volume,and $V$ is the initial volume.
Rearranging for the change in volume: $\Delta V = \frac{PV}{B}$.
The initial volume of the sphere $V = \frac{4}{3} \pi r^3$,where $r = 10\,cm = 0.1\,m$.
Substituting the values:
$V = \frac{4}{3} \times 3.14 \times (0.1)^3 = \frac{4}{3} \times 3.14 \times 0.001\,m^3$.
Now,calculate $\Delta V$:
$\Delta V = \frac{5 \times 10^8 \times (\frac{4}{3} \times 3.14 \times 0.001)}{3.14 \times 10^{11}}$
$\Delta V = \frac{5 \times 10^8 \times 4 \times 3.14 \times 0.001}{3 \times 3.14 \times 10^{11}}$
$\Delta V = \frac{20 \times 10^5}{3 \times 10^{11}} = 6.66 \times 10^{-6}\,m^3$
$\Delta V \approx 6.7 \times 10^{-6}\,m^3$.