A medicine capsule is in the shape of a cylinder with two hemispheres struck to each of its ends (see figure).
A medicine capsule is in the shape of a cylinder with two hemispheres struck to each of its ends (see figure). The length of the entire capsule is 14 mm and the diameter of the capsule is 5 mm. Find its surface area.
Surface area of the cylindrical part $=2 \pi \times \mathrm{r} \times \mathrm{h}$
$=2 \pi \times\left(\frac{\mathbf{5}}{\mathbf{2}}\right) \times 9 \mathrm{~mm}^{2}=45 \pi \mathrm{mm}^{2}$
Sum of the curved surface areas of two hemispherical parts.
$=2\left\{\mathbf{2 \pi} \times\left(\frac{\mathbf{5}}{\mathbf{2}}\right)^{2}\right\} \mathbf{m m}^{2}=25 \pi \mathrm{mm}^{2}$
Total surface area of the capsule
$=45 \pi+25 \pi \mathrm{mm}^{2}=70 \pi \mathrm{mm}^{2}$
$=70 \times \frac{\mathbf{2 2}}{\mathbf{7}} \mathrm{mm}^{2}=220 \mathrm{~mm}^{2}$