Science:Math Exam Resources/Courses/MATH215/April 2014/Question 03 (b)/Statement

A small mass can move along the x-axis between two large masses located at $x=-1$ and $x=2$. When subjected to a linear drag its position $s(t)$ obeys the differential equation:

$\displaystyle s''(t)={\frac {-1}{(s+1)^{2}}}+{\frac {4}{(s-2)^{2}}}-s'(t),\quad -1<s<2$

(b) Find the equilibrium solution of the first order system from (a).