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Question
The diameter of a coper sphere is 18 cm. The sphere is melted and is drawn into a long wire of uniform circular cross-section. If the length of the wire is 108 m, find its diameter.
Solution
Given that diameter of a coper sphere = 18cm.
Radius of the sphere = 9cm
Length of the wire = 108m
= 10,800cm
Volume of cylinder = volume of sphere
⇒ `πr_1^2h=4/3πr_2^3`
⇒`r_1^2xx10800=4/3xx9xx9xx9⇒r_1^2=0.09`
∴Diameter =2 ×0.3=0.6cm
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