Question

The thickness of a metal pipe is 1.5cm. the inner diameter is 21cm. What is the volume of metal required for a metal pipe of length 7cm

Answer 1

volume of metal pipe is 742.5 cmcube

Answer 2

r=10.5 cm
R=10.5+1.5 =12cm
h=7cm
volume= pi R²h  - pi r²h
=pi x h (R² - r²)
=22/7 x 7 (R+r)(R-r)
=22 x (12+10.5)(12-10.5)
=22 x 22.5 x 1.5
=742.5cm³

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