# Damping motion~

1. Feb 18, 2006

### yukcream

if the amplitude of a damped oscillation is decrease to 1/e after n periods, how can i show that the frequency is about [1-(8pi^2n^2)-1]times the frequency of undamped ocillations? can i assume that the oscillation is critical damping such that the term b/2m and k/m can be cancel in the expression of the damped frequency and natural freuency relation?

thanks for attention!!

yukyuk

2. Feb 18, 2006

### Physics Monkey

You know the damping factor and the modified period in terms of the undamped period and the damping constant. You should probably start by evaluating the damping factor after n periods and setting it equal to 1/e.

3. Feb 19, 2006

### yukcream

To physics monkey,

Thanks for your help but i cannot understand what you mean? how can i write out the relation between the damped period and undamped~ quite confusing !! Also why I start by evaluating the damping factor after n periods and setting it equal to 1/e????

yuk

4. Feb 19, 2006