Fig. 1.

Vpython code of the computational model (left), and graphical interface (right). The code includes two definitions of graphical objects: the “box” (line 9) which imports the motion diagram of the real object (marked in red dots) and a green sphere (defined as “s” in line 10) which moves according to a computational model. The green trace of the sphere is compared to the red pattern of dots that was produced from a video of a falling paper clip using the Tracker software