I just have the circles so far, with the radii and current (x,y) positions.

And i forgot to mention that I want the circles to stop when they reach the upper boundary of the rectangle/

applet. And they should move in forward direction only ,i.e. theta = [0, 180] (randomly generated and known beforehand, say A moves 90degree continuosly from its previous position, B in 60 and C in 120 degrees respectively).

Each circle should move in a speed given by a ratio. say, Speed of A: B : C = 1: 2 : 3.

And i want to knwo the x,y coordinates after every period of, say 10seconds. (which i think i can get using basic trigonometry, and speed,distance,time thing. Is there any other way like a method or something ?).

Thanks.