# Having issues with a seemingly simple problem

1. Nov 13, 2011

### Xyius

1. The problem statement, all variables and given/known data
A particle of mass m is repelled from the origin by a force inversely proportional to the cube of its distance from the origin. Set up and solve the equations of motion if the particle is initially at rest at a distance $x_0$ from the origin.

(This is one dimensional motion)

2. Relevant equations
Newtons Second Law to set up the equation of motion

3. The attempt at a solution
The first part is simple. I just had..
$$m \ddot{x}=\frac{k}{x^3}$$

And this part is right. I am having trouble solving it however. I know it is just a method from my differential equations course but I am having trouble for some reason!

2. Nov 13, 2011

### rude man

Try conservation of energy - potential + kinetic.