The radii of external and internal surfaces of a hollow spherical shell are 6cm and 3cm respectively. if it is melted and recast into a solid cylinder of height 7cm, then the diameter of the cylinder is
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radii of external surface = R = 6cm
radii of internal surface = r = 3cm
volume of sphere = 4/3Π(R^3-r^3)
also, volume of cylinder = Πr^2h
4/3Π(R^3-r^3) = Πr^2h
4/3(6^3-3^3) = r^2 7
4/3(216 - 27) = r^2 7
4/3(189) = r^2 7
4(63)/7 = r^2
4*9 = r^2
36 = r^2
6 = r
Tell, if the answer is wrong.
radii of internal surface = r = 3cm
volume of sphere = 4/3Π(R^3-r^3)
also, volume of cylinder = Πr^2h
4/3Π(R^3-r^3) = Πr^2h
4/3(6^3-3^3) = r^2 7
4/3(216 - 27) = r^2 7
4/3(189) = r^2 7
4(63)/7 = r^2
4*9 = r^2
36 = r^2
6 = r
Tell, if the answer is wrong.
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