A football player attempts a 30‐yd field goal. If he is able to impart a velocity u of 100 ft/sec to the ball, compute the minimum angle θ. for which the ball will clear the crossbar of the goal. (Hint: Let m = tan θ)

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?