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1.1. Glider on an air-cushion track

Constant Velocity and Force

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A far spread misconception relates a constant velocity with a constant driving force. The video shows the classical experiment of a glider on an air-cushion track to demonstrate the physics of a movement with constant velocity. However, many evaluation studies have shown, that this misconception about a constant velocity and a constant driving force is a very robust one. We permanently experience in our daily life that it needs a force to move things around and this experience seems to neutralize the results of physics teaching.

As an addition to the classical air-cushion experiment it may be helpful to confront students with the physics interpretation of scenes from daily life, where objects move with constant velocity. The following 7 videos show such scenes. When shown and discussed with students (possibly more than ones) a conceptual change towards a Newtonian interpretation may be supported.

air_cushion_track.mpg (10 MB)

air_cushion_track.wmv (0,7 MB) (lower resolution)