- #1
DB
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Lately there has been a lot of talk about this kinda stuff and I am beginning to understand it but I think the best way to fully understand it is if I write it out and ask you guys. Let's say that one mass is orbiting another in space and all we know is the mass of both planets and the gravitational force acting on the smaller planet and we were asked to find the Total energy.
[tex]F=G(\frac{m_1m_2}{r^2})[/tex]
[tex]r=\frac{\sqrt{Gm_1m_2}}{F}[/tex]
Edit: This should be
[tex]r=\sqrt{\frac{Gm_1m_2}{F}}[/tex]
----------
[tex]E_{total}=E_k+E_p[/tex]
----------
[tex]E_k=\frac{1}{2}mv^2[/tex]
[tex]v_{planet}=\frac{(2\pi r)^2}{(2\pi\sqrt{\frac{r^3}{GM}
)^2}}[/tex]
----------
[tex]E_{potential.grav.}=-\frac{Gm_1m_2}{r}[/tex]
----------
Knowing:
[tex]r=\sqrt{\frac{Gm_1m_2}{F}}[/tex]
[tex]v_{planet}=\frac{(2\pi r)^2}{(2\pi\sqrt{\frac{r^3}{GM}
)^2}}[/tex]
Then:
[tex]E_{total}=\frac{1}{2}mv^2-\frac{Gm_1m_2}{r}[/tex]
How'd I do? (probably not to well )
Thanks
[tex]F=G(\frac{m_1m_2}{r^2})[/tex]
[tex]r=\frac{\sqrt{Gm_1m_2}}{F}[/tex]
Edit: This should be
[tex]r=\sqrt{\frac{Gm_1m_2}{F}}[/tex]
----------
[tex]E_{total}=E_k+E_p[/tex]
----------
[tex]E_k=\frac{1}{2}mv^2[/tex]
[tex]v_{planet}=\frac{(2\pi r)^2}{(2\pi\sqrt{\frac{r^3}{GM}
)^2}}[/tex]
----------
[tex]E_{potential.grav.}=-\frac{Gm_1m_2}{r}[/tex]
----------
Knowing:
[tex]r=\sqrt{\frac{Gm_1m_2}{F}}[/tex]
[tex]v_{planet}=\frac{(2\pi r)^2}{(2\pi\sqrt{\frac{r^3}{GM}
)^2}}[/tex]
Then:
[tex]E_{total}=\frac{1}{2}mv^2-\frac{Gm_1m_2}{r}[/tex]
How'd I do? (probably not to well )
Thanks
Last edited: