One mole of tungsten (6.02 × 1023 atoms) has a mass of 184 g, and its density is 19.3 g/cm3 , so the center-to-center distance between atoms is 2.51 × 10−10 m. You have a long, thin bar of tungsten, 2.9 m long, with a square cross section, 0.16 cm on a side. You hang the rod vertically and attach a 425 kg mass to the bottom, and you observe that the bar becomes 1.47 cm longer. From these measurements, it is possible to determine the stiffness of one interatomic bond in tungsten. Use g = 9.8 m/s 2 throughout this problem. What is the spring stiffness of the entire wire, considered as a single macroscopic (large