The damped oscillator equation is
m¨x+b˙x+kx=0
And its solution has natural frequency ω0
ω0=√km−(b2m)2
However, when one adds a driving force to the equation
m¨x+b˙x+kx=Dcos(Ωt+ϕ)
the resonance frequency Ω=ωR that maximizes amplitude is
ωR=√km−2(b2m)2
I'm wondering why the resonance frequency isn't the natural frequency. I've read this formulas in the wikipedia page of the harmonic oscillator.
No comments:
Post a Comment