Chapter 24, Problem 69CP

(a)

To determine

The proof that the magnitude of the electric field at distance $x$ from the center and inside the slab is $\rho xl/{\epsilon }_0$.

(b)

To determine

The proof that the electron exhibits simple harmonic motion with frequency equal to $\frac{1}{2\pi }\sqrt{\frac{\rho e}{m_{\text{e}}{\epsilon }_0}}$.