4. The beam is fabricated from three members nailed together to support the loads shown in Fig. 4(a). The cross-sectional dimensions are given in Fig. 4(b). (a) Find the location of the centroid of the cross-section. (2 points) (b) Compute the moment of inertia about the neutral axis for the cross-sectional area. (2 points) (c) Check whether the maximum bending stress developed in the beam is smaller than the allowable stress llow 1150 psi. (3 points) - (d) Check whether the maximum shear stress developed in the beam is smaller than the allowable stress allow 100 psi. (3 points) (e) Determine the required spacing s for the nails if each nail can resist a maximum shear force of 300 lb. Assume that the nails are equally spaced for the entire beam. (5 points) 600 lb 50 lb/ft 6150 lb-ft B 5A- 6 A 6 ft Figure 4(a) I in. 1 in. 10 in. 12 in. 8 in.- Figure 4(b)