An alternative for teaching and learning the simple diffusion process   using Algodoo animations
  In this work animations of the random walk movement using a freeware Algodoo were done in order to support teaching the concepts of Brownian Motion. The random walk movement were simulate considering elastic collision between the particles in suspension in a fluid, and the particles which constitute the fluid. The intensity of velocities where defined in an arbitrary range, and we have a random distribution of the velocity directions. Using two methods, the distribution histogram of displacements (DHD) and the mean-square-displacement ${\langle{\Delta r^{2}}\rangle}$ (MSD), it was possible to measure the diffusion coefficient of the system, and determine the regions where the system presents ballistic regime or diffusive transport regime. The ballistic regime was observed graphically when the MSD has a parabolic dependence with time, which differing from the typical diffusive regime where MSD has a linear dependence. The didactical strategy for combining analytical approaches as graphic analysis, and animations in software's with easy implementation supports the teaching and learning processes, especially in Physics were we want to explain experimental results within theoretical models. 
Samir L. da Silva, Judismar T. Guaitolini Junior, Rodrigo L. da Silva,   Emilson. R. Viana and F\'abio F. Leal
physics.ed-ph