The surface area of a solid metallic sphere is 616 cm2. It is melted and recast into a cone of height 28 cm. Find the diameter of the base of the cone so formed .
Surface area of the sphere
⇒ 4πr2 = 616
⇒ r2 = 49
⇒ r = √49
⇒ r = 7 cm
Diameter of base = 7 × 2
= 14 cm