Question

2.2 cubic dm of brass is to be drawn into a cylindrical wire 0.25cm in diameter. find the length of the wire.

Answer 1

Solution:-

Let the length of the wire be 'h' cm
1 dm = 10 cm
Volume of metal = 2.2 dm³ = 2.2(10 cm)³
= 2.2*1000
Volume of metal = 2200 cm³
Let 'r' be the radius of the cylinder.
Given : Diameter = 0.25 cm 
So, r = 0.25/2 
r = 0.125 cm
Volume of metal in the wire = 2200 cm³
∴ πr²h = 2200 cm³
⇒ 22/7*(0.125)²*h = 2200
⇒ h = (2200*7)/22*0.015625
⇒ h = 15400/0.34375
h = 44800 cm
Or 44800/10 
 Height = 4480 dm
Answer.

Answer 2

Answer:

Let the length of the wire be 'h' cm

1 dm = 10 cm

Volume of metal = 2.2 dm³ = 2.2(10 cm)³

= 2.2*1000

Volume of metal = 2200 cm³

Let 'r' be the radius of the cylinder.

Given : Diameter = 0.25 cm 

So, r = 0.25/2 

r = 0.125 cm

Volume of metal in the wire = 2200 cm³

∴ πr²h = 2200 cm³

⇒ 22/7*(0.125)²*h = 2200

⇒ h = (2200*7)/22*0.015625

⇒ h = 15400/0.34375

h = 44800 cm

Or 44800/10 

 Height = 4480 dm