A copper wire of diameter 6 mm is evenly wrapped on a cylinder of length 18 cm

We have,

Diameter of the coppe wire, $d=6 \mathrm{~mm}=0.6 \mathrm{~cm}$,

Radius of the copper wire, $r=\frac{0.6}{2}=0.3 \mathrm{~cm}$,

Length of the cylinder, $H=18 \mathrm{~cm}$,

Radius of the cylinder, $R=\frac{49}{2} \mathrm{~cm}$

The number of rotations of the wire on the cylinder $=\frac{\text { Length of the cylinder, } H}{\text { Diameter of the copper wire, } d}$

$=\frac{18}{0.6}$

$=30$

The circumference of the base of the cylinder $=2 \pi R=2 \times \frac{22}{7} \times \frac{49}{2}=154 \mathrm{~cm}$

So, the length of the wire, $h=30 \times 154=4620 \mathrm{~cm}=46.2 \mathrm{~m}$

Now, the volume of the wire $=\pi r^{2} h$

$=\frac{22}{7} \times 0.3 \times 0.3 \times 4620$

$=1306.8 \mathrm{~cm}^{3}$

Also, the weight of the wire $=$ Volume of the wire $\times$ Density of the wire

$=1306.8 \times 8.8$

$=11499.84 \mathrm{~g}$

$\approx 11.5 \mathrm{~kg}$