The continuous beam is designed to support the loads shown in Fig. $4($a$).$ The beam is fabricated

from four timber members nailed together. The cross$-$sectional dimensions are given in Fig. $4($b$).$

$($a$1)$ Determine the reactions at $A.$

$($a$2)$ Draw the shear force diagram for the beam ABC.

$($a$3)$ What is the maximum shear force found in the beam?

$($b$1)$ Find the location of the centroid of the cross$-$section.

$($b$2)$ Compute the moment of inertia about the neutral axis for the cross$-$sectional area.

$($c$)$ Determine the maximum shear stress in the beam.

$($d$)$ Determine the shear flow passes each of the nails.