u/SonOfGustaf99

This is from a quiz I had, so I hope this follows the homework rules? I don’t have my attempt in front of me but I’ll type out approximately what I wrote:

I was asked about the group and phase velocities. I wrote down a positive group velocity since the envelope is moving positively and a negative phase velocity since the phase is moving negatively with respect to the envelope. Then I wrote that these waves are standing waves because if you look at x=30, there is a peak in every frame (or the phase moves in sync with the frame rate which would just be a dumb thing to sneak in on a quiz lol) which says to me that the phase is not moving and that it is just the envelope that is moving in the positive x-direction. Is this correct? I am unsure about if my inclusion about these waves being standing waves is true. Could you weigh in? Thanks!