Engineering Properties of Grains

A spherical seed of diameter $d = 3.0\text{ mm}$ ($0.003\text{ m}$) has volume $V = \frac{\pi}{6} d^3 \approx 1.4137 \times 10^{-8}\text{ m}^3$ and surface area $A = \pi d^2 \approx 2.8274 \times 10^{-5}\text{ m}^2$. The specific surface area per unit volume $S_v = A / V = \frac{6}{d} = \frac{6}{0.003}$ in $\text{m}^{-1}$ is: