The diameter of a sphere is 42 cm. It is melted and drawn into a cylindrical wire of diameter 2.8cm then find the length of the wire answer usGiven
diameterofasphere=42cm
radius=
2
42
=21cm
Now,
Volumeofsphere=
3
4
πr
3
=
3
4
×
7
22
×21×21×21
=4×22×21×21
=3,8808cm
3
Volumeofsphere=volumeofcylinder
38,808=πr
2
h
⇒38808=
7
22
×14×14×h
h=
11
696
h=63
Hence,lengthofwireis63cm.