The diameter of a metallic sphere is equal to 9 cm. It is melted and drawn into a long wire of diameter 2 mm having uniform cross-section. Find the length of the wire.
Volume of the metallic sphere=volume of the wire(cylinder in shape)
Radius of sphere 
cm
=4.5 cm
Volume of sphere = 
3
3
Radius of cylinder 
= 1mm =0.1cm
Volume of cylinder 
r2h
⇒ πr2h 
3
⇒ r2h 
R3
⇒ 0.1 × 0.1 × h = 
× 4.5 × 4.5 × 4.5
⇒ 0.1 × 0.1 × h =4 × 1.5 × 4.5 × 4.5
⇒ h = 12150 cm
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