General Considerations

When a block is put into the tray the inserted mass affects the motion of the tray. To experienced physicists this is a question concerned with dampened harmonic motion, and the recognition of this will determine the observations made. To a typical student there are a large number of observations (sinking, twisting) not linked to the theoretical background but nevertheless to do with the motion of the "wig-wag."

A third group of pupils will include other observations (rattling) which are observable but which do not necessarily relate to the variables in the task.