Both federal child labor laws and Massachusetts state law concur that the minimum age to work is 14 (with some exceptions). But child labor laws in each state may vary regarding the minimum age to work and which permits are needed. When there is a conflict between federal and state laws, the strictest law will apply. Although 14 is the official age Massachusetts youth generally begin working, there are exceptions.
The moment of inertia, otherwise known as the angular mass or rotational inertia, of a rigid body is a tensor that determines the torque needed for a desired angular acceleration about a rotational axis.
The first equation I came across shows my moment of inertia as: I = pi/64(D^4-d^4) where; D= outer diameter of pipe. d= inner diameter of pipe. I have also come across another equation for moment of inertia in a paper regarding HDD installation loading and stress analysis. This equation is to find the pulling load within a curved section of HDD. They used moment of inertia to ultimately determine the Normal forces applied to the pipe.