二维平面波 §1波动的基础知识 P(x, 3, t)=o cos(kx+ly-wt +a) =2x 丌,2丌 k 2T2T v L2丌,2兀 TK V K C≠/C.2+c§1 波动的基础知识 2 2 ; 2/ 2 ; 2/ 2 ; 2/ 2 x y y y x x C c c T K K L C T l l L c T k k L c ≠ + = = = = = = = = = ν ν π π ν ν π π ν ν π π K ˆ k l ϕ(x, y,t) = ϕ cos(kx + ly −νt +α ) 0 二维平面波