# Homework Help: Period of small oscillations in central potential

1. Dec 2, 2005

### Chen

Hi,

A particle is subjected to a central potential of:

$$V(r) = -k\frac{e^{-\alpha r}}{r}$$
Where $$k, \alpha$$ are known, positive constants.

If we make this problem one-dimensional, the effective potential of the particle is given by:
$$V_{eff}(r) = -k\frac{e^{-\alpha r}}{r} + \frac{l^2}{2 m r^2}$$
Where the second term is the "centrifugal potential", $$l$$ is the absolute value of the angular momentum the particle has.

Now suppose that this effective potential has a minimum at $$r_0$$, which is known, so that if placed there the particle will have a circular motion.

The question is - what is the period of small oscillations (in the r-dimension) around the circular orbit?
The answer needn't depend on the energy of the particle or its angular momentum.

Thanks,
Chen

2. Dec 2, 2005

### Tom Mattson

Staff Emeritus
You know the rules: Post what you've got so far, and we'll help from there.

3. Dec 3, 2005

### Chen

I've solved it myself. Thank you very very much.