Strength of Materials

1434 (fl. singer 4th edition)
Determine the maximum torque that can be applied at 1.0 m from the right end of the shaft, without causing excessive rotation.

Problem: A frame consists of two bars joined rigidly at B and built in
at A and C (see Figure). Determine the bending moment M at B
and the compressive force P in AB when, due to a rise in temperature,
the bar AB increases in length by

Answer. P and M can be found from the equations:

/reviewer/mechanics-and-strength-of-materials/solution-to-problem-205-axial-deformation
please see this,,, sir/madam,,, why is it in problem 206
/reviewer/mechanics-and-strength-of-materials/solution-to-problem-206-axial-deformation

Good day. May I ask if the 900 lb load in C is really downward? I think it is upward to maintain the shear of the 900 right? If it would be downward then the shear will be zero? Correct me if I'm wrong. Thanks!