From erwarzeski:

I finally figured out how to get to this simulation through the NTNU physics simulations website, Through the "Ahmed's Additions" link.  Your additions to the original NTNU simulations are very useful and welcome.  I had posted a message on a different window on the site, but I'm not sure that would get to you.

The Superposition of Two Waves simulation is the only one I have found online that will allow me to change the phase angle between two waves traveling in the same direction.  Is it possible to put a background grid on the display?  The center-line/rest position of each of the waves would need to fall on one of the lines.  I would like my students to measure the amplitudes of the original waves, and to compare those quantitatively with the amplitude of the combined wave as they change the phase angle.

Bob Warzeski

E. Robert Warzeski, PhD
Thomas Jefferson High School for Advanced Studies
17 Gretna Boulevard
Gretna, Louisiana, USA  70118

[quote] Is it possible to put a background grid on the display? [/quote]
I think this what he ask.