66 cubic cm of silver is drawn into a wire 1 mm in diameter. Calculate the length of the wire in metres.
Given,
Volume of the wire = 66 cm3
Diameter of the wire = 1 mm
Radius (r) of wire = 12 = 0.5 mm = 0.05 cm
Let the length of the wire be l
As,
Volume of the wire = 66 cm3
⇒ πr2l = 66
⇒ 227 × 0.05 × 0.05 × l = 66
⇒ l = 66 × 722 × 0.05 × 0.05
Therefore,
l = 8400 cm = 84 m
So,
The length of the wire is 84 m.