Find the length of 13.2 kg of copper wire of diameter 4 mm, when 1 cubic cm of copper weighs 8.4 gm.
Given,
weight of copper wire = 13.2 kg
Diameter of wire = 4 mm
Radius of wire = 
Let length of wire = h cm
so,
weight of 1 cubic cm wire = 8.4 gm
= 
= 
38