Carbon dioxide (CO2) is an example of a linear quadrupole (Figure 4.55). Determine the total potential at a point (a) (x, 0) and (b) (0, y) for y > a. In each case, show that V ? 1/r^3 for r >> a, where r is the distance from the origin. (c) Overlay the graph of the variation of electric potential along the x-axis with that of the absolute value of its variation along the y-axis. (d) At what distance b along the y-axis does |V(r = 0, v = b)| = 2 x V (r = b. v = 0)?

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