# Science:Math Exam Resources/Courses/MATH215/April 2014/Question 03 (d)

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MATH215 April 2014

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### Question 03 (d)

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

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

(d) Sketch the phase plane (vector field) and include several possible solution curves.

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