Question

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

Answer 1

We have,

Side of cubical block$$=7\,cm.$$

Then radius of hemisphere $$=\dfrac{7}{2}\,cm=3.5\,cm.$$

Then,

Total surface area of the solid=Total surface area of cube-Area of base of hemisphere +curved surface area of hemisphere.

$$ \Rightarrow TSA=6\times {{7}^{2}}-\pi \times {{\left( 3.5 \right)}^{2}}+2\pi {{\left( 3.5 \right)}^{2}} $$

$$ \Rightarrow TSA=332.465\,\,\,c{{m}^{2}}. $$

Hence, this is the answer.