A bar that is 1.5 in. long and 0.25 in. in diameter is subjected to a tensile stress of 5000 psi. The bar is also inadvertently twisted. Cracks are observed to appear at an angle shown with θ0 = 65°
(a) Determine the torque that was applied.
(b) If there had been no initial tension, what torque could have been applied without cracking?