Question

Find the length of 13.2 kg of copper wire of diameter 4 mm, when 1 cubic cm of copper weighs 8.4 gm.

Answer 1

Density of copper = Weight/Volume = 8.4 gram/1 cm³ = 8.4 gram/cm³
Volume = Weight/Density = 13.2 kg x 1000 gram/kg/8.4 gram/cm³ = 1571.43 cm³

`"L"="V"/(pi r^2)=(1571.43"cm"^3)/(22/7xx(0.2"cm")^2= 12500.01`cm = 125 m

Thus, length of 13.2 kg of copper is 125 m.