# Solving ODE using mathematica

1. Sep 8, 2008

### Winzer

1. The problem statement, all variables and given/known data
I need to solve:
[itex] a=-\frac{1}{y[t]^2}+Exp[-y[t]]y'[t]
[itex]
Using Mathematica. I have tried NDsolve and nothing.
By the way a is acceleration,y is position,and y' is velocity.
y[0]=1000000, y'[0]=0,y''[0]=0

2. Relevant equations

3. The attempt at a solution
I have tried NDsolve and nothing.
Totally at a loss. This is this right equation this problem of mine by the way[checked with the prof]. I just need to graph a[t],y[t], and v[t].

2. Sep 10, 2008

### tiny-tim

Hi Winzer!

Do you mean $$a=-\frac{1}{y[t]^2}+e^{-y[t]}y'[t]$$ ?

That's y2e-y dy / (ay2 + 1) = dt

(you need to type [noparse]$$before and$$ after for LaTeX on this forum[/noparse] )