Question

The radius of a metallic sphere is $9cms.$ It was melted to make a wire of diameter $4mm.$
find the lenght of the wire.

Answer 1

$\begin{array}{c}Volumeofsphere=\frac{4}{3}\pi r^3\\ =\frac{4\pi }{3}\times {\left(9\right)}^3\\ Volumeofcylinder=\pi r^{2}h=\pi {\left(0.2\right)}^2\times h\\ fromquestion\\ \pi {\left(0.2\right)}^{2}h=\frac{4\pi }{3}\times {\left(9\right)}^3\\ h=\frac{4}{3}\times {\left(9\right)}^3\times \frac{1}{{\left(0.2\right)}^2}=24300cm\\ \therefore length=24300cm=243m\end{array}$