<PRE><B>Question 782166</B>
A spool of copper wire hass a mass of 4.26 kg.
 How long is the wire in the spool if the wire has a diameter of 2.2 mm?
( The density of copper is 8.96g/cm3)
:
Find the number of cu/cm of copper in the original mass
{{{(1000*4.26)/8.96}}} = 475.446 cu/cm, which is 475446 cu/mm
:
let x = length of the wire (in mm)
{{{pi*1.1^2*x}}} = 3.801327x cu/mm
:
3.801237x = 475446
x = {{{475446/3.801237}}}
x = 125076.76 mm
which is
125076.76/1000 = 125 meters is the length of the wire

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