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 $R$.