This is the FIRST Internet hyperbook. All topics have user interaction and/or animation. That is why this qualifies as a hyperbook. The user interactions are facilitated by the use of simple sliders. The animations presented here are not just cartoons of particle movements. All of the particle motions presented in physicsanimation.org obey laws of physics to the extent of reasonable numerical accuracy. Also the code used to compute the motions as well as the graphics is readily accessible. It is hoped that the learner has enough curiosity to view the code via whatever browser they are using.f