Question

a cone of a metal with base 7cm and height 9cm melted to make wire of diameter 4mm. find the length of the wire

Answer 1

volume of cylinder = volume of cone
$\pi {r}^{2} \: h = \frac{1}{3} \: \pi {r}^{2} \: h$
${2}^{2} \times h = \frac{1}{3} \times \frac{49}{4} \times 9$
h=49×3/16
h=9.18cm