Quiz

1.

Why is the first term in equation (2) zero?

$$\begin{split} &\int_{-\infty}^{\infty}M(x)\frac{\partial^2... ...left(\frac{\partial M(x)}{\partial x}\right)^2\,dx \end{split}$$

2.

Equation (8)

$$x = \sqrt{-\frac{g}{2a}}\ln\left(\frac{M_0-M}{M+M_0}\right)$$

is sensible only for -g/2a>0. Why are we sure that this condition is satisfied?