Chapter 9, Problem 89CE

(a)

To determine

Show that the minimum electron energy is equal to $U_{\text{electrons}}=\frac{9h^2}{80m_{\text{e}}}{\left(\frac{3{\pi }^2{M}^5}{m_{\text{P}}^5}\right)}^{\frac{1}{3}}\frac{1}{R^2}$ .

(b)

To determine

Show that minimum total energy occurs when $R=\frac{3h^2}{8G}{\left(\frac{3{\pi }^2}{m_e^3{m}_P^{5}M}\right)}^{\frac{1}{3}}$

(c)

To determine

The radius of a star that has same mass as that of sun $\left(2\times {10}^{30}\text{kg}\right)$ .

(d)

To determine

The white dwarfs are comparable to the size of earth.