3. The assembly is composed of three solid rods with cylindrical cross-sections. One load of P = 26 kips is applied to the assembly at flange A, two loads of Q = 21 kips are applied at B, and two loads of R = 32 kips are applied at C. The normal stress magnitude in aluminum rod (1) must be limited to 20 ksi. The normal stress magnitude in steel rod (2) must be limited to 34 ksi. The normal stress magnitude in brass rod (3) must be limited to 22 ksi. Determine the minimum diameter required for each of the three rods. A (1) B Q C -R (3) R D