SOLVED:Two waves have the same angular frequency ω, wave number k and amplitude A, but they differ in phase: y1=A cos(k x-ωt) and y2=A cos(k x-ωt ϕ) . Show that their superposition is also a simple harmonic wave, and determine its amplitude as a function of the phase difference ϕ.

Atomic Structure - Shapes of Orbitals & Nodes - JEE Main Chemistry Concepts

Show that for those waves whose angular frequency ωand wave number k obey the dispersion relation k^2 c^2=ω^2 constant, the product of the phase and group velocities is equal to c^2 ^v gp h=c^2, where c is the speed of light. | Numerade