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Question
A solid rectangular block of metal 49 cm by 44 cm by 18 cm is melted and formed into a solid sphere. Calculate the radius of the sphere.
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Solution
Volume of rectangular block = 49 × 44 × 18 cm3
= 38808 cm3 ...(1)
Let r be the radius of sphere
∴ Volume = `4/3pir^3`
= `4/3 xx 22/7 xx r^3`
= `88/21 r^3` ...(2)
From (1) and (2)
`88/21 r^3 = 38808`
`=> r^3 = 38808 xx 21/88 = 441 xx 21`
`=>` r3 = 9261
`=>` r = 21 cm
Radius of sphere = 21 cm
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