# A cubical block of side 7 cm is surmounted by a hemisphere. What is the greatest

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A cubical block of side 7 cm is surmounted by a hemisphere. What is the greatest diameter the hemisphere can have? Find the surface area of the solid.[Use π = 22/7]

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From the figure, it can be observed that the greatest diameter possible for such hemisphere is equal to the cube’s edge, i.e., 7cm.

Radius (r) of hemispherical part = 7/2=3.5

Total surface area of solid = Surface area of cubical part + CSA of hemispherical part − Area of base of hemispherical part

= 6(edge)2 + 2π r2  - π r2

= 6(edge)2 + π r2

Total surface area of solid

=6(7)2 +22/7 x 3.5 x 3.5

= 294 +38.5

=332.5cm2