A closed cylinder has volume 2156 cm3. What will be the radius of its base so that its total surface area is minimum?
Volume of the cylinder = 2156 cm3
Formula for volume: V = πr2h
Therefore,
We need to find the value of r for which the total surface area will be minimum. Hence we rewrite the value of h in terms of r.
Total surface area = 2πr2 + 2πrh
Therefore,
Hence,
Therefore, r = 7cm is the answer