Question

the radius of a copper sphere is 9 cm. the sphere is melted and is drawn into a long wire of uniform circular cross section. if the length of the wire is 108 m, find its diametre.

Answer 1

Compare the volume of sphere and the wire to get the radius, then multiply the radius by 2 to get the diameter.

Hope this helps.

Answer 2

Answer:

Diameter = 18 cm

Radius = 18/2 = 9cm

It is melted and drawn into wire of length 108 m

l = 108 m

l = 10800 cm

Radius of cylindrical wire = r

Radius of copper sphere = R

Volume of cylindrical wire = Volume of copper sphere

pie*r*r*h = 4/3*pie*r^3

22/7*r*r*10800 = 4/3*22/7*9*9*9

r^2=10800 = 4×243

r^2*10800 = 972

r^2 = 972/10800

r^2 = 0.09

r = 0.3

So, d=r*2

d=0.3*2

d=0.6

Hope it helps you