StickyMasses is available as:
This applet models two (sticky) masses on a flat frictionless table, as shown in the figure below. Each of the masses is attached to a spring with distinct spring constant. If the balls are not stuck together, they will independently swing back and forth. If they collide, they stick together, and swing together depending on their momentum when they collided. The stickiness is assumed to exponentially decay with rate controlled by the parameter "Stickiness Decay." With reasonable decay values, after a while, the masses will separate. The plot shows the positions of the two masses as a function of time.