Looking for an analytical solution for a quadratic attractive potential well

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SUMMARY

The discussion focuses on deriving the equation of motion for a charged particle in a quadratic attractive potential well, specifically an electron influenced by a fixed proton. The force acting on the particle is described by the equation kq1q2/x², leading to the second-order differential equation d²x/dt² = c/x². The participant seeks an analytical solution, noting the singularity at x=0 may result in a transcendental solution. A method is suggested involving the transformation x'' = x' dx'/dx to convert the equation into a first-order format, allowing for integration and eventual solution.

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I am trying to derive an equation of motion for a simple electrostatic potential well.

Imagine a scenario where an electron (or other charged particle) is released from an arbitrary distance from a fixed (unperturbable) attractive charge (say a proton fixed in space).

In 1 dimension, the force on the particle should be kq1q2/x2

Which should yield the following second order differential equation of motion

d2x/dt2=c/x2

or x''-x-2=0

I can't seem to find an analytical solution to this equation. I'm told that due to the singularity at x=0 it will have a transcendental solution?

thanks
 
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The trick to solving equations like this one, where the independent variable t is not present, is to write
x'' = x' dx'/dx. Then you have a first order equation involving x' and x. Collect terms in x' and x, then integrate both sides. Then solve for x', and integrate a second time. This will give you an analytic solution for this equation, although it will probably be more complicated than you like.
 

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