EDIT: Damn! wrote that in the wrong forum!! mods please move to introductory physics! thanks Hi, I'm learning by myself physics of rigid bodies , and I find it kinda hard. Well, I know calculating the moments of Inertia is useless cause You have a table with all the MoI. This is not a specific problem i ran into but I'll write it anyway: 1. The problem statement, all variables and given/known data Calculate the Moment of inertia of a rotating(about it's center of mass) solid wheel of mass M( assume it's homogeneous) 2. Relevant equations I= integral of something :PPP 3. The attempt at a solution well i just know that the moment of inertia of a ring of mass M is MR^2/2 seems kinda intuitive,I'd like to know how do I (using integrals) calculate the MoI of a solid sphere as stated above. Thank you in advance! Any advice\comment appreciated.