Determine the polar moment of inertia of the area shown with respect to point O. Hint: your calculations should show J (semi-circle) – J (rectangle). For extra credit: Find the polar moment of inertia about the centroid of the area. Extra credit hint: Apply the PAT one time for the whole shape. Once you know “a" moment of inertia for a shape, you can apply the PAT to that shape. This is a "sneaky" way to find the moment of inertia about a centroid location. We can apply PAT to any shape – it does not have to be one of the standard shapes we find in a published table.) (Answer to check your work: Jo = 13.09(10®) in*) 12 in. 8 in. +6 in. 6 in.

Determine the polar moment of inertia of the area shown with respect to point O. Hint: your calculations should show J (semi-circle) – J (rectangle). For extra credit: Find the polar moment of inertia about the centroid of the area. Extra credit hint: Apply the PAT one time for the whole shape. Once you know “a" moment of inertia for a shape, you can apply the PAT to that shape. This is a "sneaky" way to find the moment of inertia about a centroid location. We can apply PAT to any shape – it does not have to be one of the standard shapes we find in a published table.) (Answer to check your work: Jo = 13.09(10®) in*) 12 in. 8 in. +6 in. 6 in.