Two cylindrical rods AB and BC are welded together at B and loaded as shown. Knowing that the average normal stress must not exceed 175 MPa in rod AB and 150 MPa in rod BC, determine the smallest allowable values of d1 and d2. 300 mm 250 mm B C 40 kN -d₂ 30 kN

2. (3 points) When loading is applied at a point on a body, the stress distributions at different cross sections are different. However, the stress distribution becomes uniform at locations far from the applied load. This is due to which principle? Name the principle. P Load distorts lines located near load P P C C Lines located away from the load and support remain straight P O avg A section a-a section b-b section c-c -Load distorts lines located near support Your answer

P = 300N ، a=140mm , b=240mm , d=26mm

3. An ASTM A36 structural steel beam 5.00 m long is placed between two rigid supports. When the temperature is 20°C, there is no stress in the bar. Compute the stress developed in the beam if the temperature rises to 45°C. Assume that the proportional limit is 235 MPa. a = 11.7 x 10-6 1/C° E = 207 GPa 4. In question 3, assume that the bar is free to elongate or shorten, calculate the change in the length of the bar if the temperature drops from 20°C to -20°C.