The steel pipe has an inner diameter of 2.75 in. and an outer diameter of 3 in. The pipe is fixed at C and subjected to the horizontal 20-lb force acting on the handle of the pipe wrench at its end. Determine: (a) the stresses in the pipe acting at point B, which is located on the surface of the pipe, (b) the principal stresses acting at this point. Sketch the element in each case.