Last updated at Dec. 8, 2016 by Teachoo

Transcript

Example 10 A copper rod of diameter 1 cm and length 8 cm is drawn into a wire of length 18 m of uniform thickness. Find the thickness of the wire. Volume of copper rod = Volume of wire Volume of copper rod Copper rod is in form of cylinder with Diameter of rod = 1 cm So, radius = r = 1/2 cm And, length = height = h = 8 cm Volume of copper rod = ๐๐2โ = ฯร(1/2)^2ร8 = ฯร 1/4 ร 8 = 2๐ cm3 Volume of wire Wire is form of cylinder with radius = r length = height = h = 18 m = 18 ร 100 = 1800 cm Volume of wire = ๐๐2โ = ๐๐2ร1800 = 1800๐๐2 cm2 Now, Volume of copper rod = Volume of wire 1800๐๐2=2๐ 1800๐2=2 r2 = 2/1800 r2 = 2/1800 r2 = 1/900 r = โ(1/900) r = โ(1/(30 ร 30)) r = โ(1/ใ30ใ^2 ) r = 1/30 So, r = 1/30 cm โด Thickness of wire = Diameter of wire = 2r = 2 ร1/30 = 1/15 cm

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Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He provides courses for Mathematics from Class 9 to 12. You can ask questions here.