00:01
We're told that the centroidal polar area moment, a j .c.
00:07
Bar, i'm going to call it i here because if you continue on in this book, you realize that the letter j is used for mass moment of inertia.
00:16
And i taught classes in mechanical engineering where everybody, by the time they were juniors, were confused about area and mass moments of inertia and j and c and everything else and using the wrong.
00:31
Thing in the wrong place.
00:33
So i'm going to call it i subar.
00:35
And that's what it is.
00:38
If you have ix, iy, then this is ir.
00:45
So i are of the 24 square inch shaded area is 600 inches to the fourth.
00:55
Determine the polar area moments, irb and ird of the shaded area.
01:01
At knowing that ird equals to irb and d equals 5 inches.
01:09
All right, so we're given our information here about the cross section and the centroidal properties...