The green curve is the parametric plot of the path
and the blue curve is the parametric plot of the path
. The point masses
move along the green and blue curves, respectively, as the time
varies. As we can see, both paths are sinusoidal functions with chosen amplitudes
. The Demonstration keeps track of the distance between the two point masses, and the rate of change of this distance with respect to time
, that is, the time derivative of the distance.