Math, asked by princelumar, 1 year ago

the volume of a metallic cylindrical pipe is 748 cm cube its length is 14 cm and its external radius is 9 cm find its thickness

Answers

Answered by 5U8H0J1T

let internal radius be r
then
π*(9)²*14-π*r²*14=748
or 9²-r²=748/π*14
or r²=81-(748/44)
or r²=81-17
or r²=64
or r=8
then thickness of pipe is =9-8=1cm....(ans)

princelumar: outstanding bro

Answered by TheLostMonk

given length (h)= 14 cm

according to question ,

volume of cylindrical pipe = 748 cm^3

πr^2 h = 748

r^2= 748 × 7 /22× 14

r^2 = 748 /44

r^2 = 17

r = 4.1 cm

since, external radius = 9 cm

then, thickness of pipe
= 9 - 4.1 = 4.8 cm = 5cm( approximate )
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Your answer : thickness = 4.8 cm
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5U8H0J1T: it is calculated as internal radius of pipe so we have to .

TheLostMonk: if have given volume of whole cylinder then no need to subtract volume of cylinder from external to internal. you just have to find internal radius because external radius already have given there.

TheLostMonk: radius is 4.1 cm

princelumar: just take internal radius as r and put the formula of volume of cylinder - volume of cylinder

TheLostMonk: at google some website showing answer = 1 or some website showing answer = 4.8 but 4.8 is correct because already we have given external radius of pipe so we have just to find internal radius and have to subtracf it from external radius

princelumar: radius is 8 cn

TheLostMonk: no by , no need to subtract two volumes , because external radius already given there which is = 9cm

princelumar: answer is mentioned in my book as 1cm

princelumar: and i also found it as 1cm

TheLostMonk: that is wrong answer in your book , plz use your brain

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