Multiple choice

The radius of a sphere is 6 cm. It is melted and drawn into a wire of radius 0.2 cm. The length of the wire is

  1. 81 m

  2. 80 m

  3. 75 m

  4. 72 m
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The volume of the sphere is (4/3) * pi * 6^3 = 288 * pi. The wire is a cylinder with volume pi * r^2 * h = pi * (0.2)^2 * h = 0.04 * pi * h. Setting 288 * pi = 0.04 * pi * h, we get h = 288 / 0.04 = 7200 cm, which is 72 m.

AI explanation

The volume of the sphere is calculated as 4/3 * pi * 6^3 = 288 * pi cubic cm. This volume equals the volume of the wire, forming the equation 288 * pi = pi * (0.2)^2 * l. Solving for the length l gives l = 288 / 0.04 = 7200 cm, which is equal to 72 m.

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