Great tutorial! A small correction: friction only relates to collisions with other objects (whereas air drag is more like "air friction"). Also my recommendation is for any future videos to capture at 60fps, since this really makes a difference in smoothness especially when showing off Physics.
Let me know when you're done with the series and we'll link to it on our /tutorials/ page. (We can link to a youtube playlist, but if you want to put up an index page or something with the .hype doc that can work too!).