The internal and external diameters of a sphere are 8 cm and 10cm respectively. The sphere neither floats nor sinks in a liquid of specific gravity `1.5g*cm^(-3)`. Calculate the density of the material of the sphere.

Explanation

Let the density of the material of the given sphere be `rho`.
According to the condition of floatation,
volume of the sphere `xx` density of the material of the sphere
= volume of displaced liquid `xx` density of that liquid
or, `{4/3pi(5)^(3)-4/3pi(4)^(3)}xxrho=4/3pi(5)^(3)xx1.5`
or, `{(5)^(3)-(4)^(3)}xxrho=(5)^(3)xx1.5`
or, `(125-64)rho=125xx1.5`
or, `rho=(125xx1.5)/61=3.07g*cm^(-3)`.