Question

28. A copper wire of diameter 6 mm is evenly wrapped on a cylinder of length 15 cm and diameter 49
cm to cover its whole surface. Find the length and volume of the wire. If the density of copper be 9 g
per cubic cm, find the weight of wire​

Answer 1

Answer

Given,

Diameter of the copper wire = 6 mm = 0.6 cm

Radius of the copper wire = 0.3 cm

Length of the cylinder = 15 cm

Diameter of the cylinder = 49 cm

Radius of the cylinder =49/2cm

Density of the copper = 9g

Number of the rotations on the cylinder =15/0.6= 25 cm

Base circumference of the cylinder = 2πr =22/7×49/2= 154 cm

So,

Length of the wire = 154 × 25 = 3850 cm

Volume of the wire = πr2h

=22/7× 0.3 × 0.3 × 3850 = 108.9 cm³

Weight of the wire = volume × density

= 108.9 × 9 = 980.1 gm