Page 5 - Lesson Notes-2-Ch.13 SA and Volumes(Cylinder)

Example-8
A metal pipe is 77 cm long. The inner diameter of cross section is 4 cm, the outer
diameter being 4.4 cm. Find the volume of metal used to make the pipe.
Solution
Given, Length of pipe(h) = 77 cm R = 4.4 = 2.2 cm
2
4
r = = = 2 cm
2
2
Volume of metal used= Volume of a hollow cylinder = π(R - r ) h
2
22
2
2
= ((2.2) − 2 ) × 77
7
22
= (4.84 − 4) × 77
7
22
3
= (0.84) × 77 = 203.28 cm
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