- #1
fluidistic
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Homework Statement
I'm trying to teach myself Small Oscillations in Classical Mechanics. So far I've read in Landau, Golstein, Wikipedia and other internet sources but this subjet seems really tough to even understand to me.
What I understand is that if we have a potential function that depends only on the position (to make it simple, let's keep it in 1 dimension) and that function has a minimum say in x0, then we can approximate U(x) close to U(x0) by using a quadratic. To be more exact, we use a Taylor's polynomial of order 2 centered in x0. So far so good.
Now, how does this help in finding say the fundamental frequencies of a system?!
Problem #1 in my university assignments for CM is "Find the frequencies for small oscillations if [itex]U(x)=V \cos (ax)-Fx[/itex]."
So first I think I should find the minimum of this function to get x0. I found it to be [itex]x_0=\frac{\arcsin \left ( \frac{-F}{Va} \right) }{a}[/itex].
I notice that the argument of the arcsine function has to be within -1 to 1 to even make sense, so that I get a condition on F and Va.
But now what...? I'm totally stuck. Should I use a Taylor's polynomial and what does it have to see with the frequencies of oscillations?