Question

A metal container in the form of a cylinder is surmounted by a hemisphere of the same radius. The internal height of the cylinder is 7 m and the internal radius is 3.5 m. Calculate: the total area of the internal surface, excluding the base.

Answer 1

Radius of the cylinder = 3.5 m

Height = 7 m

Total surface area of container excluding the base = Curved

surface area of the cylinder + area of hemisphere

`= 2 pi"rh" + 2pi "r"^2`

`= (2xx22/7 xx 3.5 xx 7) + (2 xx 22/7 xx 3.5 xx 3.5)`

= 154 + 77 m² 

= 231 m²