To compute the shear stress in a flexible member, we will use the transverse shear stress formula:

3) To find the first moment of area Q, slice through the cross section at H in a direction perpendicular to the direction of the shear force.

4) Consider the area starting at the cut through point H and going away from the neutral axis (i.e., the z axis in this configuration). Q is the moment of this area about the neutral axis.