I was wondering does increasing the frequency of a sound wave increase the energy of that wave? Because v = f * λ and P = mv and E^2 = m^2*C^4 + p^2*C^2 so therefore by increasing the frequency wouldn't this also increase the energy? Thanks, EDIT: Also in the case of a sound wave could the equation E=pc be used as the object is massless? but would this also mean that momentum also equals zero and the wave has no energy? or is the mass of the medium through which the wave travels the mass in this case?