Question

The solid cube of copper having a side length 12cm is melted to form a cylindrical wire of diameter 1cm . What will be the length of wire.​

Answer 1

Given,

A cube of copper whose edge(a) = 12cm and

The diameter of cylindrical wire (d) =  0.7 cm

∴ The radius of cylindrical wire (r) =  0.35 cm

To find, the length of the wire = ?

∴ The volume of cube = 12 × 12 × 12 = 1728 cm^{3}cm3

The volume of cylindrical wire =\pi r^{2}h=πr2h

= \dfrac{22}{7} \times 0.35\times0.35\times h722×0.35×0.35×h

According to question,

The volume of cylindrical wire = The volume of cube

\dfrac{22}{7} \times 0.35\times0.35\times h722×0.35×0.35×h = 1728

⇒ 22 × 0.05 × 0.35 × h = 1728

⇒ 0.385 × h = 1728

⇒ h = 4488.31 cm

Hence, the length of the wire = 4488.31 cm