This should be simple but I'm not sure whether I'm doing it right or not... I have a rod rotating about its edge #1. Rod's length is L and its mass is M. There is a point mass m on the rod, 3/4 L away from the edge #1, and on the other edge (#2) there is a sphere of radius R and mass m1. I need to find the moment of inertia of the whole system. I know that I need to use parallel axis theorem for the point mass, but what should I do with the sphere? Is it I = (1/3) ML^2 + m (0.75L)^2 + m1*(L)^2 + (2/5)m1*R^2 or I = (1/3)ML^2 + m (0.75L)^2 + (2/5)m1*R^2? I think it is the first option, but I'm not sure. Thank you!