The channel section carries a uniformly distributed load totaling 6W and two concentrated loads of magnitude W. (a) Verify that the neutral axis is located at d = 50 mm and that the moment of inertia about that axis is 15.96 x 106 mm*. (b) Determine the maximum allowable value for W if the working stresses are 40 MPa in tension, 80 MPa in compression, and 24 MPa in shear. A 1.0 m 6W (total) 4 m B 1.0m W 20 mm-140 mm- 140 mm FIG. P5.90 20 mm -20 mm d