27 solid iron spheres each of radius x cm are melted to form a sphere with radius y cm,find the ratio of x:.

Question

27 solid iron spheres each of radius x cm are melted to form a sphere with radius y cm,find the ratio of x:.

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Nho 5 years 2021-07-16T18:12:26+00:00 1 Answers 403 views 1

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  1. Giakhanh
    2
    2021-07-16T18:13:37+00:00
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    Answer:

    Radius of 1 solid iron sphere =r


    ⇒Volume =34πr3


    ⇒Volume of 27 solid iron spheres =27×34πr3


    ⇒34πr′3=27×34πr3


    r′3=2πr3


    ⇒r′=3r


    (ii) Surface area =4πr2


    SA r′=4πr′2


    =4π(3r)2=36πr2


    S′S=36πr24πr2=91=1:9


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