After my success with the space - time diagram I thought I'd take on an easier challenge of a charge in a B field. Here the charge enters the field at an angle causing it to move in a helical path. Quite simple to construct (In GeoGebra of course), the radius is calculated from B, v, m and q and the coordinates of the particle are given by the (rcos(2πft), rcos(2πft)). This gives the circle, to get a helix add a third coordinate v_yt.

My first year class tried out the Thermodynamics simulation (GeoGebra) I can't remember ever having such a quiet class. Feedback on the exercise was very positive. Strange that as I was walking through reception Barbara (who works there) was playing Simon and Garfunkel the sound of silence. I used to own an Alfa spider (the car in the film :-).