Question

Question 8 (i)
30 circular plates, each of radius 14 cm and thickness 3 cm are placed one above the another to form a cylinder solid. Find

(i) The total surface area.

Answer 1

Given, radius of a circular plate, r = 14 cm
Thickness of the circular plate = 3 cm
Thickness of 30 circular plates $=30\times 3=90cm$
30 circular plates are placed one above the another to form a cylinder solid. Then,
(i) Total surface area of the cylindrical solid so formed
$=2\pi r(h+r)=2\times \frac{22}{7}\times 14(90+14)$
$=44\times 2\times 104=9152c{m}^2$
Hence, the total surface area of the cylinder solid is $9152c{m}^2$.