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Probability

Question

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The inner diameter of a cylindrical wooden pipe is 24 cm and its outer diameter is 28 cm. The length of the pipe is 35 cm. Find the mass of the pipe, if 1 cm³of wood has a mass of 0.6 g.

Solution

∵ Inner diameter = 24 cm
∵ Outer diameter = 28 cm
∵ Outer radius (R) =

28 over 2 space cm equals 14 space cm

Length of the pipe (h) = 35 cm Outer volume =

straight pi

R²h

equals 22 over 7 cross times left parenthesis 14 right parenthesis squared cross times 35 equals 21560 space cm cubed

Inner volume =

straight pi

r²h

equals 22 over 7 cross times left parenthesis 12 right parenthesis squared cross times 35 equals 15840 space cm cubed

Volume of the wood used = Outer volume – Inner volume
= 21560 cm³ – 15840 cm³ = 5720 cm³∴ Mass of the pipe = 5720 x 0.6 g
= 3432 g = 3.432 kg.

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