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

Using spherical coordinates [tex](r, \theta, \phi)[/tex], obtain the Hamiltonian and the Hamilton equations of motion for a particle in a central potential V(r).

Study how the Hamilton equations of motion simplify when one imposes the initial conditions [tex]p_{\phi}(0) = 0[/tex] and [tex]\phi (0) = 0[/tex]

3. The attempt at a solution

I have obtained a Hamiltonian

[tex]H = \frac{1}{2m} \left( p_r^2 + \frac{p_{\theta}^2}{r^2} + \frac{p_{\phi}^2}{r^2 \sin^2{(\theta)}} \right) + V(r)[/tex]

and from this also the equations of motion

[tex]\dot{r} = \frac{p_r}{m}[/tex]

[tex]\dot{\theta} = \frac{p_{\theta}}{mr^2}[/tex]

[tex]\dot{\phi} = \frac{p_{\phi}^2}{r^2 \sin^2{(\theta)}}[/tex]

[tex]m \ddot{r} = \frac{1}{m} \left( \frac{p_{\theta}^2}{r^3} + \frac{p_{\phi}^2}{r^3 \sin^2{(\theta)}} \right) - \frac{\partial V}{\partial r}[/tex]

[tex]m^2 \left( 2r \dot{r} \dot{\theta} + r^2 \ddot{\theta} \right) = \frac{p_{\phi}^2 \cos{(\theta)}}{r^3 \sin^3{(\theta)}}[/tex]

[tex]2 \dot{r} \sin{(\theta)} \dot{\phi} + r \left( 2 \cos{(\theta)}\dot{\theta} \dot{\phi} + \sin{(\theta)} \ddot{\phi} \right) = 0[/tex]

But how should I proceed with the last part of the problem?

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# Homework Help: Hamiltonian mechanics

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