# Energy in relation to a forced oscillator

1. Oct 9, 2015

### shanepitts

1. The problem statement, all variables and given/known data
Find the driving frequencies at which the mechanical energy of the forced oscillation is 64 % of its maximum value. (Do not assume weak damping.)

2. Relevant equations
E∝A2ω2, where A is amplitude & ω is the angular frequency.

3. The attempt at a solution

Of course this problem is connected to a previous forced oscillator problem, where the values of c,m,k,& Fo are given. Here, I would like to know how to approach this problem and if the currents step I took are correct?

Thanks

2. Oct 13, 2015

### BvU

Hello there,

No responses so far, so let me make a few comments:
Your problem statement is far from complete, so it's hard to guess what you are supposed to do.
Your relevant equations are incomplete too. Previous results (e.g. the $A(\omega)$ expression in the solution attempt seem to come out of the blue.
If $E\propto A^2\omega^2$ then $E(\omega) = 0.64 \, E_{\rm max} \ \Leftrightarrow\ A\omega = 0.8 (A\omega)_{\rm max}$, and not $0.64 \, E = A_{\rm max}^2\omega^2$ (unless I miss something -- in which case I would like to see intermediate steps...)

Is that a start ?