Solution to Problem 123 Shear Stress

Problem 123
A rectangular piece of wood, 50 mm by 100 mm in cross section, is used as a compression block shown in Fig. P-123. Determine the axial force P that can be safely applied to the block if the compressive stress in wood is limited to 20 MN/m2 and the shearing stress parallel to the grain is limited to 5MN/m2. The grain makes an angle of 20° with the horizontal, as shown. (Hint: Use the results in Problem 122.)



Solution 123


Good day po, ask ko lang sana kung bakit involved na agad yung sec(20) sa Normal Area at hindi 100 times 50 muna. If I am not mistaken, yung Normal Area is 5000mm^2 lang naman kasi yun yung area perpendicular to the force P.