<html><head><style type="text/css"></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt"><div>You can do the overlays in Etoys by using its paint tool to paint out (using transparent paint) the middle of the frames so the others will show through. Also take a look at <a href="http://www.vpri.org/pdf/rn2005001_learning.pdf">http://www.vpri.org/pdf/rn2005001_learning.pdf</a> which shows this, and another way to do the measuring by putting frames side by side and using the height of translucent rectangles to do the measuring. There are several key techniques here to keep in mind, even with high school students. One is the "7 + or - 2" principle of not trying to jam too many ideas at once into the For the 5th graders we did fun and games with speed and acceleration several months before dropping objects off the roof of the school. The kids used the translucent rectangles here to get some visual memories of these ideas. (Both Newton and Einstein like to do math first -- to provide concepts and vocabulary -- before looking at the physical world. The translucent rectangles also help a lot with measuring errors (and the fact that you only have pixels, and there is some motion blur in the videos). What you want is for the differences that are clearly shown when the translucent rectangles are overlaid should look to be of constant size ("pretty nearly" as Newton would say). This gives rise to the hypothesis of constant acceleration, which is then tested by making a simulation with constant acceleration and finding some way to see if the video and the simulation match up. The 10 year olds found some good ways to do this. If the kids could really measure accurately, they would find that the acceleration is not actually constant, but differs by about one part in a million from 14 feet above the ground and at the ground level (due the more accurate inverse square Newton "Law"). Please don't hesitate to ask questions. Cheers, Alan </div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"> <div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><hr size="1">From: Walter Bender <walter.bender@gmail.com> To: Jeff Elkner <jeff@elkner.net> Cc: iaep@lists.sugarlabs.org Sent: Sat, March 20, 2010 12:41:01 PM Subject: Re: [IAEP] Gravity for Beginners... kino will let you export your movie as a series of stills... I am sure there are many Free multimedia programs with a similar capability. regards. -walter On Sat, Mar 20, 2010 at 3:17 PM, Jeff Elkner <<a ymailto="mailto:jeff@elkner.net" href="mailto:jeff@elkner.net">jeff@elkner.net</a>> wrote: > Hi All, > > I'm working on a derivative version of "Gravity for 10 Year Olds" to > use with my high school age students, which I'm calling "Gravity for > Beginners": > > <a href="https://docs.google.com/Doc?docid=0ARq50A7-FeDXZGd2MnN0ODJfMjAwNmc0NHF4ZHI&hl=en" target="_blank">https://docs.google.com/Doc?docid=0ARq50A7-FeDXZGd2MnN0ODJfMjAwNmc0NHF4ZHI&hl=en</a> > > Day 2 has the following: > > "Show the students how to overlay frames from their videos to get this effect:" > > Can anyone point me to easy instructions on how to do this?  I can't > really use the lesson without it. > > Thanks! > > jeff elkner > _______________________________________________ > IAEP -- It's An Education Project (not a laptop project!) > <a ymailto="mailto:IAEP@lists.sugarlabs.org" href="mailto:IAEP@lists.sugarlabs.org">IAEP@lists.sugarlabs.org</a> > <a target="_blank" href="http://lists.sugarlabs.org/listinfo/iaep">http://lists.sugarlabs.org/listinfo/iaep</a> > -- Walter Bender Sugar Labs <a target="_blank" href="http://www.sugarlabs.org">http://www.sugarlabs.org</a> _______________________________________________ IAEP -- It's An Education Project (not a laptop project!) <a ymailto="mailto:IAEP@lists.sugarlabs.org" href="mailto:IAEP@lists.sugarlabs.org">IAEP@lists.sugarlabs.org</a> <a href="http://lists.sugarlabs.org/listinfo/iaep" target="_blank">http://lists.sugarlabs.org/listinfo/iaep</a> </div></div> </div> </body></html>