How Can I Solve an ODE in Mathematica for Acceleration, Position, and Velocity?

[Winzer]

Homework Statement

I need to solve:
[itex]a=-\frac{1}{y[t]^2}+Exp[-y[t]]y'[t]<br /> $Using Mathematica. I have tried NDsolve and nothing.<br /> By the way a is acceleration,y is position,and y' is velocity.<br /> y[0]=1000000, y'[0]=0,y''[0]=0<br /> <br /> <h2>Homework Equations</h2><br /> <h2>The Attempt at a Solution</h2><br /> I have tried NDsolve and nothing.<br /> Totally at a loss. This is this right equation this problem of mine by the way[checked with the prof]. I just need to graph a[t],y[t], and v[t].$[/itex]

 

[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] )