Question

✨✔️A copper wire, 3mm in diameter,is wound about a cylinder whose length is 12cm, and diameter 10cm, so as to cover the curved surface of the cylinder. Find the length and mass of the wire, assuming the density of copper to be 8.88g per cm cube.

Answer 1

When copper wire is wounded

its cross sectional diameter would be taken as height in one round

So 3 mm = 3/10 cm height in 1 round

As length of cylinder is 12 cm

so total no of rounds= 12× 10/3 = 40 rounds

In 1 round length of wire = length of cross sectional cylinder = 2 pie r = 2 × 22/7 × 10/2

= 44/7 × 5 = 220/7= 31.4

in 40 rounds length = 31.4 × 40=1256 cm

Volume of wire = take wire cross,sectional area × length
= pie r^ 2 × 1256

= 22/7 × 3/20 × 3/20 × 1256

= 22× 9× 1256/ 2800

= 198 × 1256 /2800 = 248688/2800= 88.73

As density = 8.88

So mass/volume = 8.88

mass = 8.88 × volume = 8.88 × 88.73= 787.83 gm


✌✌✌Dhruv✌✌✌✌✌✌

Answer 2

Hey mate....

here's the answer......

3 mm =
3/10 cm height in 1 round

As length of cylinder is 12 cm

so total no of rounds=
12× 10/3 = 40 rounds

In 1 round length of wire =
length of cross sectional cylinder =
2 pie r = 2 × 22/7 × 10/2

= 44/7 × 5 = 220/7= 31.4

in 40 rounds length = 31.4 × 40=1256 cm

Volume of wire
= take wire cross,sectional area × length
= pie r^ 2 × 1256

= 22/7 × 3/20 × 3/20 × 1256

= 22× 9× 1256/ 2800

= 198 × 1256 /2800 =
248688/2800= 88.73

As density = 8.88

So mass/volume = 8.88

mass
= 8.88 × volume =
8.88 × 88.73= 787.83 gm


Hope it helps ❤️