A cuboidal block of side 7cm is surmounted by a hemisphere. What is the greatest diameter of the hemisphere can have also find the total surface area of the solid.
We have
side of cuboidal block= 7 cm
Clearly greatest diameter of the hemisphere is equal to the length of an edge of the cube is 7cm
Radius of hemisphere =72cm
Now, Total surface area of the solid
= surface area of the cube + curved surface area of the hemisphere - Area of the base of the hemisphere.
=(6×(edge)2−πr2+2πr2)cm2
={6×72+2×227×(72)2−227×(72)2}cm2
=332.5cm2