A composite beam is made by attaching the timber and steel portions shown with bolts of 12.7-mm diameter spaced longitudinally every 152.4mm. The modulus of elasticity is 10.5 GPa for the wood and 200 GPa for the steel. For a vertical shear of 5.2 |KN, determine (a) the average shearing stress in the bolts, (b) the shearing stress at the center of the cross section. (Hint: Use the method indicated in Prob. 6.55.) 63.5 101.6 mm 63.5 mm 6.5 mm 139.4 mm 6.5 mm