# How to reconstruct information from a graph of an oscillation? [closed]

We are given a graph of the position of a wave (amplitude). How can we calculate the wavelength, frequency and the maximum speed of a particle attached to that wave?

We have

Speed = wave length $\times$ frequency,

$W=2 \pi \times$ frequency ,

$V_{max}=A\times W$.

So how to calculate A?

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## closed as too localized by Qmechanic♦, dmckee♦Nov 15 '12 at 19:51

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Please help if you have any idea ? – Alpha Nov 13 '12 at 5:06
well, this is some type of sinusoid. Wavelength, in a very rough and general way, is the spatial period of the wave, the length required to come back to its original starting point. In this case, wavelength is 4 meters for B and 2 meters for A. Does the problem give more info? – Dylan Sabulsky Nov 13 '12 at 5:23
They gave me speed and they are asking frequency and max speed ? – Alpha Nov 13 '12 at 5:25
Please add that to the problem itself. When asking a question you should state the full question or the particular concept you are having trouble with, and then list what you know and/or what you've tried. – Dylan Sabulsky Nov 13 '12 at 5:28
I added please Help i am really stuck on this. – Alpha Nov 13 '12 at 5:30

## 1 Answer

$2\pi\omega \cdot A = v_{max}$ so try $v_{max}=\lambda \omega=A \cdot 2\pi\omega$. Solve for what you want, $A=\frac{\lambda}{2\pi}$ where $\lambda$ is different for each wave, as I enumerated in the comments, $\lambda_A=2$m and $\lambda_B=4$m.

I hope I answered your question right from what you're telling me. I will stress that in order to get a solid response, post your FULL question in clear terms and make sure you post everything you know and tried. Try to focus it down to conceptual questions. We want to help, but we also don't want to explicitly do your homework. Hope this helps, cheers.

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Why you used wavelength instead of A? – Alpha Nov 13 '12 at 5:57
What is A supposed to be? – Dylan Sabulsky Nov 13 '12 at 5:59
Ampltude or max of formula x=Acos(wt) which is A, – Alpha Nov 13 '12 at 6:00
I see. one moment – Dylan Sabulsky Nov 13 '12 at 6:02
Thank you, you are awesome man ! Thanks – Alpha Nov 13 '12 at 6:19