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[Some1]

I have been thinking about this for a while again but still can't figure out how to solve it or even start. I just need some help getting started on solving this:

I need to find the function r(t) from this equation:

[LATEX]\frac{1}{2}\frac{\delta r}{\delta t}-\frac{GM}{r}=-\frac{GM}{r_{0}}[/LATEX]

Extra info if needed:

[LATEX]r(0) = r_{0}[/LATEX]
[LATEX]\frac{\delta r(0)}{\delta t}=0[/LATEX]

thanks in advance
(Sorry no workings because as I said I just need a point in the right direction)

 

[Steven G]

I have been thinking about this for a while again but still can't figure out how to solve it or even start. I just need some help getting started on solving this:

I need to find the function r(t) from this equation:

[LATEX]\frac{1}{2}\frac{\delta r}{\delta t}-\frac{GM}{r}=-\frac{GM}{r_{0}}[/LATEX]

Extra info if needed:

[LATEX]r(0) = r_{0}[/LATEX]
[LATEX]\frac{\delta r(0)}{\delta t}=0[/LATEX]

thanks in advance
(Sorry no workings because as I said I just need a point in the right direction)

Sorry but I have no idea what the equation is. Maybe you should look at your post?

 

[Some1]

Does LaTeX even work on this site because I can't find instructions here and I tried all the standard LaTeX operations and nothing works...

 

[Some1]

I have been thinking about this for a while again but still can't figure out how to solve it or even start. I just need some help getting started on solving this:

I need to find the function r(t) from this equation:

1/2*(r'(t))^2 - GM/r(t) = -GM/r(0)

Extra info if needed:

r'(0) = 0

edit*Just changed it into plain text

 

[Ishuda]

I have been thinking about this for a while again but still can't figure out how to solve it or even start. I just need some help getting started on solving this:

I need to find the function r(t) from this equation:

[LATEX]\frac{1}{2}\frac{\delta r}{\delta t}-\frac{GM}{r}=-\frac{GM}{r_{0}}[/LATEX]

Extra info if needed:

[LATEX]r(0) = r_{0}[/LATEX]
[LATEX]\frac{\delta r(0)}{\delta t}=0[/LATEX]

thanks in advance
(Sorry no workings because as I said I just need a point in the right direction)

On this boad use TEX (or tex) instead of LATEX
I need to find the function r(t) from this equation:

\(\displaystyle \frac{1}{2}\frac{\delta r}{\delta t}-\frac{GM}{r}=-\frac{GM}{r_{0}}\)

Extra info if needed:

\(\displaystyle r(0) = r_{0}\)
\(\displaystyle \frac{\delta r(0)}{\delta t}=0\)

What would you do if it were written as
\(\displaystyle \frac{r_0\, r}{r_0\, -\, r}\, \delta r\, =\, 2\, G_m\, \delta t\)

 

[Some1]

Done

Oh so I have to do it that way. I was hoping there was an easier way but I have solved the problem now.

I only have to use the equation to find t when r = 0 so here the final equation is assuming r = 0:

t = \(\displaystyle \frac{\pi }{2}\sqrt{\frac{{r_{0}}^{3}}{2GM}}\)

Thankyou for your help