$8-95$ The timber beam shown in Figure $20$ is fabricated

by gluing two $15-$in$.$ and two $14-$in$.$ boards together

as shown. Determine:

$($a$)$ The maximum horizontal shearing stress in the

glued joints.

$($b$)$ The maximum horizontal shearing stress in the

wood.

$($c$)$ The maximum tensile and compressive flexural

stresses in the beam.