Acylindrical part of diameter d is loaded by an axial force p. this causes a stress of p/a, where a = πd2/4. if the load is known with an uncertainty of ±10 percent, the diameter is known within ±3 percent (tolerances), and the stress that causes failure (strength) is known within ±16 percent, determine the minimum design factor that will guarantee that the part will not fail.

In a unit cell of fcc structure, indicate the position of one of the tetrahedral interstitial sites by plotting the corresponding tetrahedron. do the same for one of the octahedral interstitial sites (in a separate fcc unit cell). mark the positions of all the tetrahedral and octahedral interstitial sites in the unit cells. how many equivalent tetrahedral sites and how many equivalent octahedral sites are contained in a fcc unit cell, respectively. what is the coordination number for a tetrahedral site and what is the coordination number for an octahedral site?