Chapter 5, Problem 23P

The force F (in N) acting between a particle with a charge q and a round disk with a radius R and a charge Qis given by the equation:

$F=\frac{Qqz}{2{ϵ}_0}(-1\frac{z}{\sqrt{z^2+R^2}})$

where ${ϵ}_{0=}\mathrm{<mn>\; 0\; </mn>}.\mathrm{<mn>\; 8\; </mn>\; <mn>\; 8\; </mn>\; <mn>\; 5\; </mn>}\times \text{1}{0}^{-\text{12}}$ C^2/(N-m²) is the permittivity constant and z is the distance to the particle. Consider the case where $Q=\text{9}.\text{4}\times \mathrm{<mn>\; 1\; </mn>}{\mathrm{<mn>\; 0\; </mn>}}^{-\mathrm{<mn>\; 6\; </mn>}}\text{C}$ ,

$q=\text{2}.\text{4}\times \text{1}{0}^{-\text{5}}$ C, and R = 0.1 m. Make a plot of F as a function of z for

$0\le z\le 0.3$ m. Use MATLAB’s built-in function max to find the maximum value of F and the corresponding distance z.