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The length of the wire of 0.2mm radius that can be drawn after melting a solid copper sphere of diameter 18cm?

Correct answer: D. 24300 m

  • A. 24.3 m
  • B. 243 m
  • C. 2430 m
  • D. 24300 m

Explanation

The sphere radius is 9 cm, so its volume is 4/3 x pi x 9^3 = 972pi cm3. The wire radius is 0.2 mm = 0.02 cm, so its cross-sectional area is pi x (0.02 cm)^2 = 0.0004pi cm2. Its length is 972pi cm3 / 0.0004pi cm2 = 2,430,000 cm = 24,300 m, so the likely error is 2,430 m from a conversion mistake.

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