Q37 of 107 Page 16

The diameters of internal and external surfaces of a hollow spherical shell are 10 cm and 6 cm respectively. If it is melted and recast into a solid cylinder of length of cm, find the diameter of the cylinder.

Diameter of internal surface =10 cm


∴ Radius of internal surface cm =5 cm


Diameter of external surface =6 cm


∴ Radius of external surface cm =3 cm


Volume of spherical shell hollow =



Height of solid cylinder cm


Let the radius of the solid cylinder be ‘r’ cm


Volume of the solid cylinder



Volume of the solid cylinder = Volume of spherical shell hollow





⇒ r2 × (8/3) = (4/3) × 98


⇒ r = 7


Diameter of cylinder = 14 cm


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