Question

A solid is composed of a cylinder with hemispherical ends. If the whole length of the solid is 104 cm and the radius of each hemispherical end is 7 cm, find the surface area of the solid.

Answer 1

Radius of the hemispherical end = 7 cm

Height of the hemispherical end = 7 cm

Height of the cylindrical part`=(104 - 2 × 7) "cm" = 90 "cm"`  

Surface area of the solid = 2(curved surface area of the hemisphere) + (curved surface area of the cylinder) 

= [2(2πr²) + 2πrh] 

= 2πr (2r + h)

`=2xx22/7xx7xx[(2xx7)+90] "cm"^2`

= (44 × 104) cm²

= 4567 cm²²