The rigid beam is supported by the three posts A. B. and C. Posts A and C have a diameter...

The rigid beam is supported by the three posts A. B. and C. Posts A and C have a diameter of 60 mm and arc made of a material lor which E = 70 GPa and σY =20 MPa. Post B is made of a material for which E' = 100 GPa and σY1 = 590 MPa. It P = 130 kN. determine the diameter ol post B so that all three posts are about to yield. (Do not assume that the three posts have equal uncompressed lengths.)