Two circular cylinders of equal volumes have their heights in the ratio 1:2. Find the ratio of two radii.
Question:
Two circular cylinders of equal volumes have their heights in the ratio 1:2. Find the ratio of two radii.
Solution:
Let, r1, r2 be the radii of the cylinder
h1, h2 be the height of the cylinder
v1, v2 be the volume of the cylinder
h1/h2 = 1/2 and v1 = v2
$\Rightarrow \mathrm{v}_{1} / \mathrm{v}_{2}=\left(\mathrm{r}_{1} / \mathrm{r}_{2}\right)^{2} *\left(\mathrm{~h}_{1} / \mathrm{h}_{2}\right)$
Since, v1 = v2
$\Rightarrow \mathrm{v}_{1} / \mathrm{v}_{1}=\left(\mathrm{r}_{1} / \mathrm{r}_{2}\right)^{2} *(1 / 2)$
$\Rightarrow\left(r_{1} / r_{2}\right)^{2}=(2 / 1)$
$\Rightarrow\left(\frac{r_{1}}{r_{2}}\right)=\frac{\sqrt{2}}{1}$
Hence, the ratio of the radii are √2:1