30 circular plantes, each of radius 14 cm and thickness 3 cm are placed one above the another to from a cylindrical solid . Find
(i) the total surfce area.
(ii) volume of the cylinder so formed.

Explanation

Radius of one circular plate= 14 cm.
Thickness of one circular plate = 3 cm
As the plates are placed one above the other, so the heightof the cylinder formed by placing 30 plates
`=30xx3=90 cm`
(i) Total surface area of the cylinder `=2pi rh+2pi r^(2)`
`=2pi r(r+h)=2xx(22)/(7)xx14(14+90)`
`=44xx208=9152 cm^(2)`
(ii) Volume of the cylinder `= pi r^(2)h=(22)/(7)xx14xx14xx90=55440 cm^(3)`.