Question

A solid is in the form of a cylinder with hemispherical ends of same radii. The total height of the solid is 20 cm and the diameter of the cylinder is 14 cm. Find the surface area of the solid.

Answer 1

Given that,

Height of solid = 20 cm

Diameter of cylinder = 14 cm

We have,

Height of cylinder, h = 20 − 7 − 7 = 6 cm

Radius of cylindrical and hemispherical part, r = 7 cm

Surface area of solid = Surface area of cylinder + 2 × Surface area of hemisphere

= 2πrh + 2 × 2πr²

= 2πrh + 4πr²

= 2πr(h + 2r)

= `2 xx 22/7 xx 7 xx (6 + 14)`

= 2 × 22 × 20

= 880 cm²

Hence, the surface area of a solid is 880 cm².