Determine the reactions at A and B of the beam system shown in Fig. Q1.1.3. Assume that the connections at C and D are rigid and the weight of the beams are negligible. 500 N D 4 m C 6 m 4m- 800 N 6 m B Fig. Q1.1.3 Determine the reactions at A and B of the beam in four-point bending shown in Fig. Q1.1.4. 500 N 1200 N 3m- 6 m + 3 m n 30C Fig. Q1.1.4 C X D B A y 000 Review the deformation sign conventions for S.F. and B.M..