I am learning Newtonian mechanics in high school. I understand that in rotational motion, the distance between center of mass and the rotational axis has also a role to play. So we find the "moment" of these quantities by multiplying them with $ r $.
In translational motion, we have the mass $ m $ to calculate stuff. So in rotational motion, I should use the moment of mass $ mr $ in mass's place. But why do we use the second moment, which is $ mr ^2 $ ?
I have searched around in this website, but still very confused! I hope someone can help me understand it.