Power delivered by a wave
Each part of a nice sine wave oscillates just like a mass on a spring. Hence it’s energy is that of an oscillating mass on a spring. We saw before that this depended on w2A2.
The power delivered by a wave is just this energy per time. The rate of delivery depends on the speed of the wave. Thus the power in the wave should depend on:
P ? w2A2v where ? means proportional to.