# How does an oscillating particle in a non-inertial reference frame appear?

The general question is : given an oscillating particle in a non-inertial reference frame:

• How would it appear from outside the non-inertial reference frame ?
• How would an observer inside that non-inertial reference frame see the movement of that particle?
• How different would the oscillation appear to the observer inside, in comparison to the same oscillation happening in an inertial reference frame?

This came up in the context of the following problem:

Suppose you have an incline plane (the angle is $\alpha$ ) and there's a crate with mass "M" that slides (with no friction) down the plane. On that crate there's a small pole with a tiny mass let's name it "m" tied to the pole with a weightless thread. I'm told that the mass "m" is not accelerating in respect to "M" and the question is: If I'm to give the mass m a small bump so that it's out of balance, what would be the frequency of the oscillations?

I'm not asking for a specific answer but more for conceptual guidelines.

Here is a schematic I drew:

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Hi Ord, and welcome to Physics Stack Exchange! This is a site for conceptual questions about physics, not general homework help. If you can edit your question to ask about the specific conceptual issue that's giving you trouble, I'll be happy to reopen it. See our FAQ and homework policy for more information. –  David Z Dec 26 '12 at 21:31
Ord, if you want to reply to a comment, you should do so in a comment. I've removed the parts of your post that should have been comments, rather than edits, so that you have a better idea of what comments and edits are for. Now: the issue is that your question is still too vague. It's not a specific conceptual issue yet. If you look at the homework policy, it gives some guidance on this: basically, show what you've tried so far and ask about the specific step that you get stuck on. –  David Z Dec 26 '12 at 21:58
@DavidZaslavsky I think this is no longer "too localized" it does have a "localized" example so people would know the context of the question but I think that the concepts that bother me are clear, aren't they ? –  Ord Dec 26 '12 at 22:56
Not really. It looks like all you've done is add some other questions, the ones in your first two (or three?) bullet points. But the core of your question is still the last bullet point, where you ask how to find the frequency of the mass without narrowing it down to a specific conceptual issue, and that is still too localized. In other words, what you're asking there is only useful to someone who is trying to solve this specific problem. It'll be better if you ask about a more focused concept that is involved in a large class of similar problems. –  David Z Dec 26 '12 at 23:09
You're addressing one question out of three and you say that just because it's there the others are bad too? Here, I've removed it. What's not general about oscillations in non-inertial reference frames ? –  Ord Dec 26 '12 at 23:17