1. The problem statement, all variables and given/known data Hi. I am a newbie to the Physics forum. I am actually attempting to figure out a problem where there are two bodies forced to revolve around each other. The only constraints that would exist are the distance of separation between the two bodies is assumed to be constant. And there might be an initial angular velocity. Intuitively I believe that if they are given initial equal angular velocities, the entire system will move in a straight line. And if they are having different angular velocities, the system will tend to spiral. Can any one tell me if this is right? 2. Relevant equations Here is where I get stuck...My initial attemp was to design parametric equations in the form : x1(t)=x2(t)+Rcostheta1 y1(t)=y2(t)+Rcostheta1 x2(t)=x1(t)+Rcostheta2 y2(t)=y1(t)+Rcostheta2 Now both are simultaneously varying..I am confused as to how model the same..So any tips on as to whether I am on the right track or whether I have to consider acceleration also for them to maintain that distance of separation would be appreciated.