Classical Mechanics (Kibble & Berkshire) · Problem 5.1
Energy conservation — T.W.B. Kibble, F.H. Berkshire
Physics — Mechanics · free-linear-oscillations
Problem
A certain oscillator satisfies the equation
x¨+4x=0.
Initially the particle is at the point x=3 when it is projected towards the origin with speed 2. Show that, in the subsequent motion,
x=3cos2t−sin2t.
Deduce the amplitude of the oscillations. How long does it take for the particle to first reach the origin?