16 Determine the planar density of copper atoms in a (100) plane given that the unit cell is face-centered cubic and the lattice parameter is 3.61 A. (A) 7.68 x 1018 atoms/m² (B) 1.53 x 1019 atoms/m² (C) 2.30 × 1019 atoms/m² (D) 3.84 x 1019 atoms/m² 17 A cantilever beam of length Z and rectangular cross-section hxb has a load at the end. What is the ratio of the maximum normal stress to the maximum vertical shearing stress? (A) L (B) 2L h (C) 4L h (D) 2L 18 Which of the following would most likely require a steel containing 0.6% carbon that has been spheroidized, cold-drawn, and slightly tempered? (A) a bridge beam (B) a water pipe (C) a cutting tool (D) a ball bearing