Video Analysis

If you can take a video, you can use that video to measure speeds and accelerations. The tool involved is called "video analysis software" and there are free versions that seem to work pretty well. After looking at a few, I have comments on a smaller few:

1. Tracker: My favorite so far. It is free, computer-based, open-source and looks transparent and powerful, for example:

• Fixed or time-varying coordinate system scale, origin and tilt.
• Multiple calibration options: tape, stick, calibration points and/or offset origin.
• Switch easily to center of mass and other reference frames.
• Protractors and tape measures provide easy distance and angle measurements.
• Define custom variables for plotting and analysis.

http://www.cabrillo.edu/~dbrown/tracker/
http://www.cabrillo.edu/~dbrown/tracker/help/frameset.html

2. Kinovea: a free, open-source sports analysis software with some good analysis tool including video magnification, slo-mo, data export to spreadsheets. The output looks beautiful
http://www.kinovea.org/

3. Vernier Physics: a $5 app for iPhone & iPad. Vernier is popular and looks convenient for people who already use iPhones. But it requires you to:
1. not move the camera and
2. mark each frame manually.
3. You can't export your info to a spreadsheet. 
http://www.vernier.com/products/software/video-physics/

Update(Jan'15)-Destin from Smarter Every Day shows how to analyse a grasshopper using Tracker. If that was a little fast, watch his tutorial. (Destin has linked all you need in the "show more" box of the first video.  When I tried repeating his work, the windows version of Tracker wouldn't work on every computer but the ".jar" file did. On some computers Destin's You-tube video (step #3) worked. On others, only Quicktime worked. Try stuff.