3-105. The building slab is subjected to four parallel column loadings. Determine F, and F, if the resultant force acts through point (12 m, 10 m). 12 kN F: KN 12 m. 16 m

*4-21. Replace the three forces acting on the shaft by a single resultant force. Specify where the force acts, measured from end A. -5 ft- Ai 500 lb -3f₁-2 fl ft- ft- 200 lb Prob. 4-21 12 13 -4 ft- 260 lb B

4-2) Find the megnitude and direction of the support forcas at A and B and the res tant mament

An infinitely large sheet is subjected to a gross stress of 350 MPa. There is a central crack 5/π cm long and the material has a yield strength of 500 MPa. a. Calculate the stress-intensity factor at the tip of the crack. b. Calculate the plastic-zone size at the crack tip. c. Comment upon the validity of this plastic-zone correction factor for the above case.