8 24.1 Light waves and the coherent condition of waves 4. The phase difference Simple harmonic oscillation x(t=Acos(at+o) Time( A---the amplitude 2兀 a---the angular frequency a 小- the initial phase at+o---phase 824.1 Light waves and the coherent condition of waves Sinusoidal(harmonic) waves Y(x, t)=Acos(lr-@t+o) △x Wave at t=△t Wave at t=0 k 2r ---angular wave number3 4. The phase difference Simple harmonic oscillation x(t) = Acos(ωt +φ ) A---the amplitude ω---the angular frequency φ---the initial phase ω t + φ ---phase T π ω 2 = §24.1 Light waves and the coherent condition of waves Sinusoidal(harmonic) waves Ψ (x,t) = Acos(kx −ωt +φ ) λ 2π k = ---angular wave number §24.1 Light waves and the coherent condition of waves