An aluminum tube with the hexagonal cross section shown is 2.5 ft long and has a constant wall thickness of 0.080 in. Find (a) the largest torque that the tube can carry if the shear stress is limited to 7200 psi; and (b) the angle of twist caused by this torque. Use G = 4 x 106 psi for aluminum. 1.5 in. 0.075 in. FIG. P3.44