Question

A copper wire of diameter 4 mm is drawn using 770cm cube of copper. What is approx lenght of wire drawn

Answer 1

Answer:

61.25m

Step-by-step explanation:

Volume of cube= 770 cu. cm= 770x1000 cu. mm

Area of wire= πdxd/4 = π x 4x4 /4= 4π sq. mm

Thus, length of the wire= Volume / Area= (770x1000)/(4π)

= 770x1000x7/ (4x22)

= 35x250x7= 61250mm= 61.25m

Answer 2

Given:

A copper wire of diameter 4 mm is drawn using a 770cm cube of copper.

To find:

The approx length of wire drawn from the copper.

Solution:

As given,

we have,

Volume of copper

$= 770 {cm}^{3}$

Diameter of copper wire

$= 4mm = 4 \times {10}^{ - 1} cm$

So, the radius of copper wire

$= 2mm = 2 \times {10}^{ - 1} cm$

Now,

as given

The copper wire is drawn from the 770 cm cube of copper.

So,

The volume of copper wire

$= 770 {cm}^{3}$

Also,

Copper wire is in the form of a cylinder

So,

The volume of copper wire

$= \pi {r}^{2} h$

where h = length of copper wire.

Now,

$\pi {r}^{2} h = 770$

$\frac{22}{7} \times ( { {2 \times 10}^{ - 1} )}^{2} \times h = 770$

On solving the above, we get

$h = \frac{7 \times 770 \times 10 \times 10 }{22 \times 2 \times2}$

$h = \frac{7 \times 770 \times 5 \times 5 }{22}$

$h = 7 \times 35 \times 5 \times 5$

$h = 6125 cm$

Hence, the length of copper wire is 6,125 cm.