Hi,
For an undamped mass, spring system subject to a harmonic force, the equation is: ma+kx=Fsin(ωt)
where a=d^2/dx^2
After solving the diff eqns, the steady state amplitude is:
X=(F/m)/(ω^2-ω0^2)
where ω is the frequency and ω0 is the natural frequency =sqrt(k/m)
according to the...