Question

a hollow metal sphere has an external diameter of 12 cm and a thickness of 2 cm. (i)Given that the mass of 1cm3 of the metal is 5.4g, find the mass of the hollow sphere in kg.
(ii)The hollow sphere is melted and recast to form a solid sphere. find the radius of the solid sphere

Answer 1

Answer:

volume of the metal of the sphere = (4/3)™π (6^3 - 4^3)

=(4 /3)π (216 - 64) = (4/3)π×152= 4×22×152/(3×7)=13376/21

mass = 13376×5.4/21 g = 13376×5.4/(21×1000)=3.44kg