Question

can u explain
first answer will be marked as brainliest

Answer 1

Answer:

Length of the cylinder = 24 cm Diameter of copper wire = 4 mm = 0.4 cm

Therefore, the number of rounds of wire to cover the length of cylinder

 

Now, diameter of cylinder = 20 cm

Therefore, length of wire in one round = circumference of base of the cylinder = d cm

Length of wire for covering the whole surface of cylinder = length of wire in 60 rounds

Radius of copper wire = cm = 0.2 cm

Therefore, volume of wire = r2h

 

= 474.122 cu. cm

Weight of wire = volume × density = 474.122 × 8.68 gm = 4115.38 gm = 4.11538 kg 4.12 kg

Answer 2

Solution:-

It is assumed that one round of copper wire will cover 3 mm or 0.3 cm height of cylinder.

Number of rounds = Height of the cylinder/diameter of the wire

= 12/0.3

= 40 rounds

Now,

The length of the wire required in one round = Circumference of the base of the cylinder

Diameter of the cylinder = 10 cm, so the radius = 5 cm.

circumference = 2πr

= 2*π*5

Length of wire required in one round = 10π

 Length of wire required in 40 rounds = 10π*40

= 400*22/7

= 8800/7

Length of the wire = 1257.14 cm

Radius of the wire = 0.3/2 = 0.15 cm

Volume of wire = Area of cross section of wire × length of the wire

= π*r² × 12.57

22/7 × (0.15)² × 1257.14

Volume of the wire = 88.898 cm³

Mass = Density × Volume 

= 8.88 × 88.898

Mass = 789.41 gm

Hope it helps u