Click "Go" to display the longitudinal resonant oscillation of air particles in a tube. You can choose between two models for the air particles. The "particles" model is more realistic with some random motion added to the oscillation. The "lines" model displays vertical lines of air particles at regular positions along the tube. This looks much like the coils of a slinky spring and shows how longitudinal standing waves in a spring would appear.
You can select a tube open at both ends (organ pipes and flutes act like these) or closed at the left end (such as trumpets and clarinets). A range of harmonics are able to be displayed and you can vary the oscillation amplitude from 10 to 40 pixels using the range slider.
At any stage you can click check boxes to show an undisturbed tube for comparison and links to the moving medium to show where air particles move from their equilibrium position. The links comparison works best when lines of air particles are modelled. Finally, you can display a graph of the displacement of particles/lines from their equilibrium position as time progresses.
