Find the stresses in the stepped beam shown in Fig. 12.23 when a moment of 1000 N-m is applied at node 2 using a two-element idealization. The beam has a square cross section 50 x 50 mm between nodes 1 and 2 and 25 x 25 mm between nodes 2 and 3. Assume the Young s modulus as 2.1 x 1011 Pa.