A cantilever beam of rectangular cross section (width b = 25 mm, height h = 100 mm) is loaded by a force P that acts at the midheight of the beam and is inclined at an angle a to the vertical (see figure). Two strain gages are placed at point C, which also is at the midheight of the beam. Gage A measures the strain in the horizontal direction and gage B measures the strain at an angle ( = 60o to the horizontal. The measured strains are (a = 125 ( 10-6 and (a = - 375 ( 10-6.
Determine the force and the angle ( = 60o, assuming the material is steel with E = 200 GPa and v = 1/3.