Classical Mechanics (Kibble & Berkshire) · Problem 14.11
The general theory of small oscillations — T.W.B. Kibble, F.H. Berkshire
Physics — Mechanics · liouville-damped-oscillator
Problem
A one dimensional damped oscillator with coordinate q satisfies the equation q¨+4q˙+3q=0, which is equivalent to the first order system
q˙=v,v˙=−3q−4v.
Show that the area a(t) of any region of points moving in (q,v)-space has the time variation
a(t)=a(0)e−4t.
Does this result contradict Liouville's theorem?