Answer: Thickness=[tex]\frac{2}{3}cm[/tex]

Step-by-step explanation:

• Volume of cylindrical copper wire=[tex]\pi r^{2}h[/tex]

         Given,d=1 cm so,r = 0.5 cm and h=8 cm

         ∴ Volume=[tex]\frac{22}{7}(0.5)^{2} *8[/tex]

• Now, Volume of wire which is drawn from copper wire=volume of copper wire.

   Let the radius be R.

  according to question,

        [tex]\pi R^{2}*18=\pi (0.5)^{2} *8[/tex]

    ⇒[tex]R^{2}=\frac{2}{18}[/tex]

    ⇒[tex]R=\sqrt{\frac{1}{9} }[/tex]

    ∴[tex]R=\frac{1}{3}cm[/tex]

• So, thickness of wire =[tex]2*\frac{1}{3}cm[/tex]

                                  =[tex]\frac{2}{3}cm[/tex]