This is a series of interactive pages on distance-time graphs. It is like having a motion sensor when you don't have a motion sensor.
Take Your Dog for a Walk
A clever interactive introduction to rate via distance-time graphs. The full-screen version would be useful if this is done as a whole class activity.
http://nrich.maths.org/public/viewer.php?obj_id=4803
Motion Capture
Motion capture is a similar program but graphs displacement rather than distance, so it may be useful to introduce the concept of first and second derivatives.
http://nrich.maths.org/public/viewer.php?obj_id=4873&part=
Motion Sensor
Motion Sensor tests for understanding - can you describe how a graph was made?
http://nrich.maths.org/public/viewer.php?obj_id=4872&part=
Steady Free Fall
In this rich activity, you drop a ball onto a ramp of your own design and see the graph of vertical distance versus time. Some challenging questions are asked.
http://nrich.maths.org/public/viewer.php?obj_id=4851&part=
