You have three 24 ft long wooden 2x6's and you want to nail them together them to make the stiffest possible beam. The stiffness of a beam is proportional to the moment of inertia of the beam's cross- section about a horizontal axis passing through its centroid. The actual dimensions of nominal 2x6 lumber are 1.5 in. by 5.5 in. Calculate the moment of inertia about the centroidal x-axis for each of the following beam configurations. Which configuration will be the stiffest? #IA Config b Config a COG Config c