The beam ABCD is loaded with a force, P (N) as shown in Figure 3(a). The beam cross-section is illustrated in Figure 3(b). The beam is made of a linearly elastic-perfectly plastic material with a yield strength of 210 MPa, Young's modulus of 200 GPa and Poisson's ratio of 0.3. (a) Determine the magnitude of the force, P (N) to cause the initial yield at the most critical section of the beam. (4 marks) (b) Determine the magnitude of the force, P (N) to cause fully plastic (plastic hinge) of the beam. (4 marks) (c) Determine the shape factor of the beam cross-section and briefly explain what you know the effect of this shape factor in relation to the load that can be applied to the beam. (2 marks) P(N) 0.5 m BO D 1.0 m + 0,5 m Figure Q3(a) 80 mum 30 mm 30 mm 80 mm Figure Q3(b) 30 mm