Question
A sphere of radius 21 cm is melted and recast into 66
smaller spheres of equal size. Find the radius of each smaller sphere(approximately).Solution
Volume of a sphere = (4/3)ΟrΒ³. Volume of the large sphere = (4/3)Ο(21)Β³ = (4/3)Ο Γ 9261 = 12348Ο cmΒ³. Volume of one smaller sphere = Total volume Γ· Number of smaller spheres = 12348Ο Γ· 66 = 187Ο cmΒ³. Let the radius of each smaller sphere be r. (4/3)ΟrΒ³ = 187Ο. rΒ³ = (187 Γ 3)/4 = 140.25. r = β140.25 β 5 cm. Correct answer: c) 5 cm
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