Question

Volume and surface area of a solid hemisphere are numerically equal then what is the diameter of hemisphere ?

Answer 1

Volume (Hemisphere)$=\frac{2}{3}\pi r^3$

Surface area$=3\pi r^2$

$\therefore 3\pi r^2=\frac{2}{3}\pi r^3$

$\Rightarrow r=\frac{9}{2}$

$\Rightarrow 2r=9$

$\Rightarrow d=9$.