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

[Winzer]

Homework Statement

I need to solve:
a=-\frac{1}{y[t]^2}+Exp[-y[t]]y&#039;[t]<br /> &lt;br /&gt; Using Mathematica. I have tried NDsolve and nothing.&lt;br /&gt; By the way a is acceleration,y is position,and y&amp;#039; is velocity.&lt;br /&gt; y[0]=1000000, y&amp;#039;[0]=0,y&amp;#039;&amp;#039;[0]=0&lt;br /&gt; &lt;br /&gt; &lt;h2&gt;Homework Equations&lt;/h2&gt;&lt;br /&gt; &lt;h2&gt;The Attempt at a Solution&lt;/h2&gt;&lt;br /&gt; I have tried NDsolve and nothing.&lt;br /&gt; 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].

 

[tiny-tim]

Hi Winzer!

Do you mean a=-\frac{1}{y[t]^2}+e^{-y[t]}y&#039;[t] ?

That's y²e^-y dy / (ay² + 1) = dt

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