Two aluminum bars (G=4.0 x10$^6$psi) that are the same length (36"), one square (1.5" x 1.5") and one circular (1.5" diameter), are subject to a torsion load. If the maximum shear stress is 12ksi, determine:
a. The maximum torque that can be applied to each bar
b. The angular deformation for each bar when the torque from part a is applied.