A solid copper sphere of radius 6 cm is melted and redrawn into a wire, whose radius of cross-section is 8 cm. Find the length of the wire.
Answer & explanation
Correct answer: option 3
We know that,
Volume of sphere = \(\frac{4}{3}\)πR3
Volume of cylinder = πr2h
We have,
Radius of the sphere = R = 6
radius of the cylinder = r = 8
According to the question,
= πr2h = \(\frac{4}{3}\)πR3
= 8 × 8 × h = \(\frac{4}{3}\) × 6 × 6 × 6
= 64 × h = \(\frac{4}{3}\) × 216
= h = 4.5 cm