1. The problem statement, all variables and given/known data A sphere with radius .175 cm has a density ρ that decreases with distance r from the center of the sphere according to ρ= ((2.75*10^3) kg/m^3) - ((9.25*10^3) kg/m^4)r A) Calculate the total mass of the sphere. B) Calculate the moment of inertia for an axis along the diameter. 2. Relevant equations 2.75*10^3 kg/m^3 - (9.25*10^3 kg/m^4)r Probably some sort of integral. 3. The attempt at a solution I'm sorry, but I have absolutely no idea how to even begin to do this. I tried googling, and the only result I found contained a triple integral in spherical coordinates. Given that this is on my Calc-based physics I homework and the only prerequisite is calculus I, it seems implausible that this is actually the best solution. I've never used spherical coordinates in my life, and only vaguely know how to solve a triple integral (I've taught myself a bit online, but none of my classes have ever covered them before).