A community of Physics Phans!

My friends and I have been trying to figure this out.

Question: If an object is placed a certain distance into space with no original velocity relative to the Earth, what is the object's velocity after any given amount of time?

Problem:  Everything we know about gravity is in terms of distance ().  So how do we find equations for position, velocity, or acceleration at any given time?

Will any energy conservation laws be needed?

We realized it will take some differential equations to solve, but which ones?

Thanks for any help!

Warning: is_dir() [function.is-dir]: open_basedir restriction in effect. File(/f1/content/ilovephysics/public/forum/uploads/) is not within the allowed path(s): (/f2/ilovephysics/:/nfsn/apps/php5/lib/php/:/nfsn/apps/php/lib/php/:/nfsn/content/content/nfsn/) in /f2/ilovephysics/public/forum/include/image_upload/image_upload.php on line 30