Question

A cubical block of side 7 cm is surmonted by a hemisphere. What is the greatest diameter the hemisphere can have? Find the surface area of the solid.

Answer 1

let  us assme it is sphere 
because the hemisphere has the same radius as sphere if we take with same radius 
and it is exactly surmounted by sphere so the diagonal of cube will be the diameter of sphere or hemisphere
diagonal of cube=root 3 into a
                           =7root3
therefore the diameter of hemisphere is 7$\sqrt{3}$

Answer 2

Answer:

If the cubical block is of side 7 cm then the hemispherical largest diameter will be 7cm.

Surface Area=Curved surface Area of hemisphere+ Curved Surface Area of cube - Area of the base

Surface Area=2πr^2 - πr^2+6a^2

Surface Area= πr^2+ 6a^2

Surface Area=3.14×7/2×7/2+6×7×7

Surface Area=38.465+ 294

Surface Area=332.46cm^2or(332.5cm^2)

Hope it helps you.