(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A charged particle of mass m moves non-relativistically around a circular orbit. The potential energy is U(r)= -A/r^4.

What is the sign of A and why?

Using Bohr's quantization for angular momentum to calculate the allowed values of the radius.

2. Relevant equations

F=-dV/dx

F=mv^2/r

mvr=nh/2*Pi

3. The attempt at a solution

Intuitively, I thought that A is positive, cause classically you consider that at infinity, the potential is zero. However, when I determined the radius of orbits, it turns out that r^2 is negative, and you cannot square root it!

mv^2/r=-4*A/r^5 (Centripetal force to -dV/dx)

Sub it v=nh/2*PI*m*r

and r^2 = -4*m*A/n^2*H^2 where H=h/2*PI

Could I ignore the negative sign here???

Thanks

Regards,

The Keck

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# Homework Help: Inverse fifth Law

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