Question

The diameter of a sphere is 6cm. It is melted and drawn into a wire of diameter 2 mm. Find the length of the wire.

Answer 1

2mm = 0.2cm
Radius = $\frac{6}{2}$=3
Volume of sphere = $\frac{4}{3}$$\pi$$r^3$
Volume=$\frac{4}{3}$ $\times$ 9 $\pi$
Volume=12π
Volume of wire will equal to volume of sphere therefore
Volume of wire = $\pi$$r^2$h
12π = $\pi$$r^2$h
12 = 0.4 h
30 = h