1. The problem statement, all variables and given/known data By using spherical coordinates, find the radius of inertia (Is this the same as the radius of gyration?) about the z-axis of the constant density solid which lies above the upper half of the cone x2 + y2 = 3z2 and below the sphere x2 + y2 + (z-2)2 = 4. For a constant density region E of volume V, the radius of inertia about the z-axis is defined as: VR2 = ∫∫∫(x2 + y2)dV E 2. Relevant equations ρ2 = x2 + y2 + z2 x = ρsin(φ)cos(θ) y = ρsin(φ)sin(θ) z = ρcos(φ) mR2 = I ...where R = radius of gyration and I = moment of inertia about a given axis. 3. The attempt at a solution At this stage I am beyond confused. Any assistance in beginning this question would be greatly appreciated.