Explanation:
Formula to calculate the potential at point "a" is as follows.
[tex]V_{a} = \frac{kq_{1}}{r_{1}} + \frac{kq_{2}}{r_{2}}[/tex]
= [tex]\frac{9 \times 10^{9} \times 2.2 \times 10^{-6}}{0.4} + \frac{9 \times 10^{9} \times -3.20 \times 10^{-6}}{\sqrt{(0.4)^{2} + (0.4)^{2}}}[/tex]
= -4590 V
Therefore, we can conclude that the potential at point a, which is on the x axis at x = 40.0 cm is -4590 V.
