Video Analysisusing understanding of motion to support conceptual

understanding in maths and physics

What is it?

Tracker is a video analysis tool that is free for educational use.https://www.cabrillo.edu/~dbrown/tracker/It tracks the x and y coordinates of on object on each frame of a video

Why use it

Students understand motion and can use this to build conceptual understanding of a range of topics.• Connection between displacement,

velocity and acceleration• Modeling and graphing functions• Limits and small segments in time

How I use it

• Show a video• Ask students to describe then graph

distance vs time• Describe velocity and graph that• Track the object and compare the graphs• Fit a model to the graph and discuss the

constants• Get students to take their own videos to

analyse

Taking your video

Two IMPORTANT factors● Keep your camera still● Have a clear contrast between your

object and backgroundLess important, but helpful● have 1m marked on your background

Tracking your object

• Open tracker• Import video• Select the portion of the video you want

to analyse and move the arrows to your beginning and end points

• Calibrate your measurements – defines the distances used in the analysis

• >>new>>calibration stick (This needs to be done before you track)

Tracking your motion

• Create>> point mass• Right click and rename it if

you like• Now the cool bit begins!• Right click your object

(mass A or what ever you have named it)

• Select autotracker

Tracking your motion

• Contol+ shift, select a portion of your object that is clear

• Search, then watch the magic happen!• If auto track doesn’t work, you can

manually change each frame, but that can be tedious.

Analysing the data

By selecting table, it will calculate other variables

Analysing the Data

• Right click on the table and select Analyze

• Analyze>>fit a curve will allow you to fit a function to the data. This seems to only work when there is simple motion such as a quadratic.

Analysing the Data

Select the data you want to graph. The graphs and the data can be easily exported.

Resources

There is a shared resources section on https://www.cabrillo.edu/~dbrown/tracker/made by the developers and other teachers.Youtube has a range of tutorials

How I have used it

Middle School: Analysing egg drop videosIGCSE: Introduction to quadratics and sine/cos curvesIB: Quadratics, Sine/Cos and differentiation. Great tool for students to use when doing their exploration.

In Conclusion

• It’s easy to use once you get the hang of it.

• Students find it engaging.• It helps develop students

understanding.• It’s free.• Everytime I use it with students, they

teach me a new feature.