Thank you Bill_K for your answer!
Yes I am talking about a transverse wave.
So the energy per unit length varies between 0 and ρA2ω2 along the period of the wave.
(It seems we usually define the energy to be an average over a whole period?)
But the wave transports energy in the propagation...
Hello,
consider a 1D elastic wave which have the amplitude:
A=cos(x)
What is the energy density: \frac{dE}{dx} of this wave?
I seem to recall that the energy of a wave is proportional to the square of the amplitude:
E \propto A^2
That seem to mean that \frac{dE}{dx} \propto cos(x)^2...