This is most often described in terms of angular momentum. I decided to use the rotational energy approach. I'm shooting with a high speed camera made by Vision Research. http://www.visionresearch.com/Contact-Us/Contact-Form/ - Click here to contact them with inquiries and tell them I sent you! That will be fun. Check us out on Facebook: http://on.fb.me/SED-Facebook A big thanks to Ryan Sipes - Motocross Superstar The custom music was created by "A Shell In The Pit". Support the artist by going and downloading this and many more of his songs. The name of the song is "Sike" http://ashellinthepit.com/ Download some of his music to jam to here: http://ashellinthepit.bandcamp.com/ Jumpers: Ryan Sipes, Pooh Sipes, Ben Linderman, and others