Question

A copper rod of diameter 1 cm and length 8 cm is drawn into a wire of length 18 m of uniform thickness. Find the thickness of the wire

Answer 1

For copper rod,
Diameter=1cm
Radius=1/2cm
Length=height=8cm
So,volume=pie×r^2×h
22/7×1/2×1/2×8=44/7cm^3
For wire
Since,Length=18m=1800cm
so,thickness=44/7/1800cm=0.032cm

Answer 2

$\huge{\boxed{\mathfrak{Answer}}}$

• Here, A copper rod of diameter 1 cm.
• Its length =  8 cm
• Drawn into a wire of length 18 m of uniform thickness.
• We Have To Find : The thickness of the wire.
• Rod is in the shape of CYLINDER.

The volume of cylinder = πr²h

Therefore, the volume of the cylindrical rod = π × ( 1/2 )² × 8cm³

                                                                         =  2π cm³

New wires length of the same volume will be = 18m = 1800 cm  

                                                                        (converted it to cm )                                                                                            

If " r " be the radius then the volume of cross section of the wire will be :

π × r² × 1800 cm³

Then,

π × r² × 1800 = 2π

r²                    =  1/900

r                     = 1/30

Diameter = 2 × radius

⇒ 2 × 1/30

⇒ 1/15

Hence, The thickness of the wire will be 1/15cm.