[math]\Delta v = g * I_{sp} * ln(\frac{m_1}{m_2})[/math]
The tricky part of this is the ln part. I divide by g and ISP to get ln by itself.
[math]\frac{\Delta v}{g*I_{sp}} = ln(\frac{m_1}{m_2})[/math]
Here's the trick to getting rid of the ln: raise everything to the e power.
[math]e^{\frac{\Delta v}{g*I_{sp}}} = \frac{m_1}{m_2}[/math]
From there it is indeed simple algebra to solve for m_2
[math]\frac{e^{\frac{\Delta v}{g*I_{sp}}}}{m_1} = \frac{1}{m_2}[/math]
[math]\frac{m_1}{e^{\frac{\Delta v}{g*I_{sp}}}} = m_2[/math]
And there it is solved for m_2
I'm glad I *still* have my maths before school returns ! I got to the same conclusion ^^
When entered "coding style", it should be: m1/(e^(dV/(g*isp))) = m2.
Tried to be a little more useful than a simple "I'm glad I did it" answer :tiphat: