Question

A show-piece shown in figure is made of two solids - a cube and a hemisphere. The base of the block is a cube with edge $7cm$ and the hemisphere fixed on the top has diameter $5.2cm$. Find the total surface area of the piece.

Answer 1

The Surface area of $5$ sides of cube other than with hemisphere is

$5\times 7\times 7=245c{m}^2$

The surface area of hemisphere is $2\pi \times 2.7\times 2.7=45.78c{m}^2$

The base area of circle of the hemisphere is,

$\pi r^2=3.14\times 2.7\times 2.7c{m}^2=22.89c{m}^2$

The area of upper face of cube is

$=(7^2-22.89)c{m}^2=(49-22.89)c{m}^2=26.11c{m}^2$

So total surface area of object is $(245+26.11+45.78(c{m}^2=316.89c{m}^2$