DProb. 6.10-20. The tongue, AB, of a small utility trailer is the square box section shown in Fig.
P6.10-20b. Assume that the total weight of the trailer and its load is W, and that its line of action is 1 ft
forward of the axle of the trailer, as shown in Fig. P6.10-20a. Furthermore, assume that the tongue is
effectively cantilevered from the trailer body at B. Neglect any axial towing loads on the tongue, and
consider only the static loads when the trailer hitch at A is resting on a stationary trailer ball. Determine
the maximum weight W (trailer plus load) if the allowable flexural stress in the tongue is $\sigma_{allow} = 12$ ksi
and the allowable transverse shear stress in the tongue is $\tau_{allow} = 8$ ksi.