2. (25 points) A steel (E = 207 GPa) A-frame is to be temporarily bolted to a steel beam using two ISO grade 5.8 bolts (Sp ) = 380 MPa) of size M20 x 2.5 (A, 245 mm2). The feet of the frame and the beam to which they are fastened both have a thickness of 15 mm. A steel washer of thickness 2 mm is placed between the bolt head and the foot of the frame. The nut height is 14 mm. The stiffness of the members can be approximated as 5000 MN/m a) Determine a suitable bolt length, ensuring that there is at least one thread beyond the nut. Round the length up to the nearest 5 mm