I was asked to give the eqn and proof of energy of sinosiodal waves. However, I only know the enq of sinosiodal waves on string and to prove it. Energy= 1/2 (mass per unit length).(ang. freq.)^2.(amplitude)^2.wavelength So what is the eqn of energy of general wave. It is should be almost identical to the eqn above. But what about the mass per unit length. What replaces it? Is it multiplied with wavelength to give the mass of particle per wavelength?That's merely guessing? Could anymore tell me the answer?