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Analysing motion with GeoGebra

Page history last edited by aoldknow@yahoo.co.uk 8 years, 7 months ago

In my keynote yesterday I described the use of video-capture using the free Tracker software.  I have now uploaded a pdf file describing how to do this with the example of estimating g from a video clip of a dropped tennis ball.  The avi video clip is only 0.5 sec long and taken at 29 frames per second.  The Tracker file is also uploaded as well as the Excel file of the exported (t,y) data, and the GeoGebra file showing one approach to modelling the displacement, velocity and data. 

The files are:


GeoGebra and Motion     pdf    510kb

Ball drop 30                    avi     147kb

Ball drop 30                    trk       16kb

Ball drop analysis            ggb     21kb


Have fun

Adrian     aoldknow@yahoo.co.uk


PS I reckon Sophie on her trampoline is subject to two rather different kinds of motion - when whe is in contact with the elastic membrane of the trampoline she is like a spring-mass system - and probably modelled by SHM (simple harmonic motion) - and hence a sine wave.  But when she is in the air free of the tramplone she is a projectile - like a tossed ball in 1-dimension - and hence more likely to be fitted by a quadratic function.  Hence her motion, while periodic (roughly), is probably well-fitted by a piecewise function with sinusoid arches for the lower parts and quadratic arches for the upper parts - with each pair of arches blending smoothly together.  She could put a Wiimote in her pocket and then we could monitor her vertical acceleration in realtime using Bluetooth!  For the record I am diagnosed with"atrial fibulation" which means that my heart-beat is not "sinus" - which is the medical term - but I think it is still pretty regular i.e periodic!  Adrian

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