Question

the radius of a metallic sphere is 9cm. it was melted to make a wire of diameter 4 mm find the length of the wire

Answer 1

Volume of sphere = 4/3 πr³

Find the volume:

Volume of the sphere = 4/3 π (9)³

Volume of the sphere = 972π cm³

Find the radius:

Radius = Diameter ÷ 2

Radius = 4 ÷ 2

Radius = 2mm = 0.2 cm

Find the length of the wire:

πr²h = Volume

π(0.2)² h = 972π

0.04πh = 972π

h = 972π ÷ 0.04π

h = 24300 cm

Answer: The length of the wire is 24300 cm

Answer 2

here is your answer OK dude........
DonDjAce
HERE IS YOURS SOLUTION;

◆ Let R = radius of the sphere;

◆ Now, R = 9 cm;

Volume of sphere, V1 = 43πR3 = 43π(9)3 = 972π cm3.

◆ Now, diameter of the wire = 2 mm = 0.2 cm [as 1 cm = 10 mm]

radius of the wire, r = 0.1 cm

◆ Let h = length of the wire

volume of cylinderical wire, V2 = πr2h = (0.1)2πh cm3

◆ Since the sphere is melted and recast into wire, so in this case volume of the material remains same.

So, V2 = V1

⇒(0.1)2πh = 972π

⇒0.01 h = 972

⇒h = 97200 cm

⇒h = 972 m. [ 1 M = 100 Cm]

◆ So, the length of the wire is 972 M ◆

HOPE IT HELPS