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Tracker frame times appear to be inconsistent

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Tracker time steps don't look right
Jerry Gilfoyle
52 Posts

I am using Tracker to analyze a simple projectile motion video made with 'Camera' in Windows 10. When I analyze the movie I am getting noticeably worse results than in the past. In particular, when I calculate kinetic and potential energy to test mechanical energy conservation I get large deviations from energy conservation. All of the deviations are points with a short time interval calculated using the next frame. Most of the frames have a difference dt = 0.048 s with the next frame while the suspect ones all have dt = 0.032 s. The video format is mp4. I suspect a problem with Windows 10 since this does problem does not appear in older videos. The attached file shows the original, raw analysis and the effect of setting all the time intervals to dt = 0.048 s.

Attached File: badTimeSteps.pdf

Jerry Gilfoyle

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