The volume of a circular wooden block of length 100 cm is 3850 cm^3. Find its radius.

Given,

Since the wooden block is a cylinder, the length (height) of the circular wooden block (h)= 100 cm.

The volume of a cylinder = 3850 cm³.

We know that the volume of a cylinder$={\mathrm{\pi r}}^2\mathrm{h}$ .    (Where $\mathrm{\pi }=\frac{22}{7}$ and r is the radius of the cylinder)

$\Rightarrow 3850=\frac{22}{7}\times {\mathrm{r}}^2\times 100$

$\Rightarrow {\mathrm{r}}^2=\frac{3850\times 7}{22\times 100}$

$\Rightarrow {\mathrm{r}}^2=12.25$

$\Rightarrow \mathrm{r}=3.5 \mathrm{cm}$

Therefore, the radius of the circular wooden block is 3.5 cm.