Question

A solid metal sphere is cut through its centre into 2 equal parts.If the diameter of the sphere is 3$\frac{1}{2}$ cm,find the total surface area of each part correct to two decimal places.

Answer 1

It forms 2 hemispheres of D=3.5cm
T.S.A. OF HEMISPHERE=$3\times \frac{22}{7}\times (\frac{D}{2}{)}^2$
=$3\times \frac{22}{7}\times (1.75{)}^2$
=$3\times \frac{22}{7}\times 3.0625$
=$28.875c{m}^2$