i did this in reverse very recently. I had a ball rolling on a surface whose view was set by the camera. The ball always has to roll in the direction of the camera view, so the force applied to the ball is a vector whose x-coordinate is the cosin of the angle complimentary to the angle at which the camera looks at the ball, multiplied by the ground distance (distance of the camera on the x and y plane), and therefore also the y-value of the vector is radius * sin(ang).

The same principles apply to your problem, only in reverse. I can't tell you the specifics of your problem (except that I try to avoid magic numbers like your 0.08 coefficient), but sketch out the problem in terms of a unit circle and assign variables (on paper) to EVERY part of the problem, even the things you'll discard when you actually program it. That's been my technique so far.