Question

Radius of a cylinder is $r$ and height is $h$. find the change in the volume, if the height is doubled and radius half.

Answer 1

$V={\pi r}^{2}h$

$V^1=\pi {\left(\frac{r}{2}\right)}^2\left(2h\right)=\frac{{\pi r}^{2}h}{2}$

$\therefore$ $V^1=V/2\Rightarrow \frac{\Delta V}{V}=\frac{1}{2}$