The $560-$lb

load is applied along the centroidal axis of the member. $($Figure $1)$

Figure$1$ of $1$

A diagram of a box$-$shaped member centered on A$,$ with horizontal and vertical faces. A vertical line segment rises from point a below the member through A to point a above the member, and this segment bisects a section of the member that is parallel to its left and right faces. In a plane parallel to the member's front and back faces, a diagonal line segment extends up$-$right from point b below the member through A to point b above the member, and this segment bisects another section that intersects the first section along a horizontal line through the front and back faces. Segment b$-$b is separated from segment a$-$a by $30$ degrees. A vector labeled P extends left from the member's left face, and a vector labeled P extends right from the member's right face.

Part A

Determine the magnitude of the resultant internal normal force in the member section a$-$a$.$