question_answer

An incident wave is represented by\[y(x,t)=20\sin (2x-4t).\]Write the expression for reflected wave: (i) from a rigid boundary. (ii) from an open boundary.

Answer:

                (i) The wave reflected from a rigid boundary is \[y(x,t)=-20\sin (-2x-4t)=\mathbf{20sin(2x+4t)}\] (ii) The wave reflected from an open boundary is \[y(x,t)=20\sin (-2x-4t)=-\mathbf{20sin(2}x\mathbf{+4t)}\]