A hollow circular nylon pipe (see fig) supports a load PA = 1750 lb, which is uniformly distributed around a cap plate at the top of the lower pipe. A second load PB is applied at the bottom. The inner and outer diameters of the upper and lower parts of the pipe are d1 = 2 in., d2 = 2.375 in., d3 = 2.25 in., and d4 = 2.5 in., respectively. The upper pipe has a length L1= 14in., the lower pipe length is L2 = 16 in. Neglect the self-weight of the pipes. -If PA remains unchanged, find the new value of PB (in lb) so that upper and lower parts have same tensile stress.