Question

Problem 4.32 Your answer is partielly correct. Try again. One mole of magnesium (6 x 1023 atoms) has a mass of 24 grams, and its density is 1.74 grams per cubic centimeter, so the center-to-center distance between atoms is 2.84 x 10-10 m. You have a long thin bar of magnesium, 2.9 m long, with a square cross section, 0.07 cm on a side. You hang the rod vertically and attach a 64 kg mass to the bottom, and yooberve that the bar becomes 9.28 cm longer. From these measurements, it is possible to determine the stiffness of one interatomic bond in magnesium 1) What is the spring stiffness of the entire wire, considered as a single macrascopic (large scale), very stiff spring 6758.63 Ninm 2) How many side-by-side atomic chains (long springs) are there in this wire? This is the same as the number of atoms on the bottom surface of the magnesium wire. Note that the cross-sectional area of one magnesium atom is (2.84x 10-1012 m2 Number of side-by-side long chains of atoms Top of wire Bottom of wire 3) How many interatomic bonds are there in one atomic chain running the length of the wire? Number of bonds in total length- 4) What is the stiffness of a single interatomic "spring? ks, An interatomic bond in magnesium is stiffer than a slinky, but less stiff than a pogo stick. The stiffness of a single interatomic bond is very much smaller than the stiffiness of the entire wire Answer * 1: the tolerance is +/-5% Answer * 2: the tolerance is +/-590 Answer 3: the tolerance is +/-5% Answer * 4: the tolerance is +/-5%

Answer 1