Perhaps it's a newbie question.., as you can see in this wikipedia animation
Phase velocity (red) and group velocity (green) are described
( * sorry, new users aren't allowed to use image tags)
both show "speed" in the Propagation direction
How I calculate the rise speed of a cicle
red point in transversal direction?
For example in a very simple wave like this
y(x,t) = A* sin(kx - w t), should I calculate derivative of y having x=constant?
What about in general? How to calculate the Rise speed?
Thanks for any advice
I want to know the up-down axis speed of the wave, watching at the left side of the animation, you can see "first" left most pixel going up and down, this is the vertical speed I want to really calculate