NCEES Civil Structural Depth #515 (Timber)

[cpfwvu]

I just tried to work this problem and got the wrong answer... but I can't see how. I used an angle of inverse tan(5/12) = 22.6, but they used the opposite, 67. I really don't think the solution used the correct angle. But maybe I'm crazy. Anyone else have this problem? Any insight?

 

[T2D4]

I just tried to work this problem and got the wrong answer... but I can't see how. I used an angle of inverse tan(5/12) = 22.6, but they used the opposite, 67. I really don't think the solution used the correct angle. But maybe I'm crazy. Anyone else have this problem? Any insight?

Look at the diagram in NDS. That will explain it. It has to do with the angle between grains, IIRC.