Question

The surface area of a solid metallic sphere is 1256 sq. cm. It is melted and recast into solid right circular cones of radius 2.5 m and height 8 cm. Calculate the
1) radius of the solid sphere.
2) the number of cones recast.

Answer 1

surface area of solid sphere = 4 x 3.1416 x r^2 =1256 sq. cm

so, r =10 cm ( approx)

here after recasting the volume of the solid sphere and total volume of right circular cone will remain same .

volume of solid sphere = 4/3 x 3.1416 x r^3 =4188.79 cubic cm

volume of right circlure cone = (3.1416 x r ^2 x h)/3 = 52.36 cubic cm

so, no of cones recasted = 4188.79/52.36 = 79.99 (approx) = almost 80