Hi guys, lets say we have a wave where the power P is proportionate to the square of its amplitude, which is A^2. If now we have 2 identical waves in superposition in phase, then we have an amplitude of 2A am i right? Next, we realize that because of the amplitude of the superposed waves is 2A, it seems only natural that the power of the superposed waves together become 4P, since (2A)^2= 4A^2. In this in case there seem to be a contradiction in the conservation of energy. If these waves are left alone by themselves, the total power emitted would be 2P I think, not 4P. Why is this the case? Then we consider intensity as well, if I=P/s (s is the surface area of sphere); the intensity in this case would be 4I if the 2 waves are superposed. Would the amplitude of the superposed wave, however, affect the surface area of the sphere s? If it doesn't, why would the intensity of the wave be 4I instead of 2I when these 2 waves are left alone, if the surface area s doesn't change? (because intensity is W/m^2!!) I don't get this apparent contradiction, please help, thanks guys!!