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-   -   Finding solutions to equations of motion (http://www.physicsforums.com/showthread.php?t=13717)

 Ed Quanta Feb2-04 07:37 PM

Finding solutions to equations of motion

Ok, so I am dealing with a critically damped oscillator in which the natural frequency(w) of the oscillator is equal to the coefficient of friction (y). I am given the force mfe^t and told to find a solution for x, where

x'' +2yx' +w^2 =fe^t.

How do I go about doing this? The solution that I am supposed to find is Afe^t where A=f/4

I have to solve this for f=mfe^-t also, if this requires a different strategy, let me know I guess.

 HallsofIvy Feb3-04 07:03 AM

It would help a lot if you would clarify what you are saying. There is clearly a typo in your equation: it should be
x'' +2yx' +w^2x =fe^t.

But the main problem is that you seem to be using "f" to mean at least two different things. You say "I am supposed to find is Afe^t where A=f/4". Is that f<sup>2</sup>e<sup>t</sup>? But then "I have to solve this for f=mfe^-t". Surely f doesn't mean the same thing on both sides of that equation (since me<sup>-t</sup> is not 0!).

 himanshu121 Feb3-04 07:05 AM

I doubt whether the Pro is correct

And what are the dimensions on both sides of the solution

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