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I've been teaching myself some DEs that I can use for physics and whatnot. I am comfertable with seperable equations, but I can't figure out how to solve this problem.

Let's assume we have some rocket with thrust F(t) and drag r(v), plus acceleration due to gravity, g=9.8 m/s/s.

Overall acceleration: (m is the mass, assume constant)

[tex]a(t)=\frac{F(t)}{m} - \frac{r(v)}{m} - g[/tex]

[tex]\frac{dv}{dt}=\frac{F(t)}{m} - \frac{r(v)}{m} - g[/tex]

Now as you can see, we can't move dt over to the other side, because there are multiple terms there. Can we simply distribute it across them, and get:

[tex]\int{dv}=\int{\frac{F(t)dt}{m}} - \int{\frac{r(v)dt}{m}} - \int{gdt}[/tex]

Also, we neet to relate v to t in the r(v) term, but we don't have a v(t)...

Thanks,

-Jack Carrozzo

jack _{at}_ crepinc.com

http://www.crepinc.com/

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# Non-Seperable ODE Help

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