Problem 1.239

Calculate the moment of inertia (a) of a copper uniform disc relative to the symmetry axis perpendicular to the plane of the disc, if its thickness is equal to \(b=2.0 \mathrm{~mm}\) and its radius to \(R=100 \mathrm{~mm}\) (b) of a uniform solid cone relative to its symmetry axis, if the mass of the cone is equal to \(m\) and the radius of its base to \(R\).