(Solved): In this contour plot you can see lines of equal potential. The lines are labeled with their poten ...

In this contour plot you can see lines of equal potential. The lines are labeled with their potential values in units of Volts. These potential lines are generated by a collection of point charges. Part 1: What is the minimum number of point charges that are needed to generate a potential surface like the one shown here? 3 Previous Tries Part 2: same time will move the endpoint of the line.) determine the E-field, the better this approximation becomes. Tries 7/99 Previous Tries Part 3: What is the value of the $y$-component of the electric field at the same point? HINT: Now you need to compute the partial derivative of $V$ with respect to $y$, i.e. you need to divide $\Delta V$ by $\Delta y$. Tries 1/99 Previous Tries more point: if you keep your blue point in the middle of your interval, you get faster convergence than when you select it as one of your endpoints.