[nkozyra]

I clicked on the first one and most of the animation is distracting and superfluous, like bars of a bar graph repeatedly bouncing off each other.

Does that sort of animation really promote learning? How much ornamental dressing is needed to keep visual attention but not distract?

[andybak]

Aren't they meant to be solid masses with particular collision properties? In which case showing how they collide seems to me exactly want you'd want to show.

EDIT - I just watched it with sound. I suspect you didn't and misunderstood the subject matter.