# Homework Help: Reflected and Transmitted Waves Phase changes

1. Apr 20, 2007

### smshah

1. The problem statement, all variables and given/known data

Consider an infinitely long continuous string with tension $$\tau$$. A mass M is attached to the string at x=0. If a wave train with velocity $$\frac{\omega}{k}$$ is incident from the left, show that reflection and transmission occur at x=0 and that the coefficients R and T are given.
Consider carefully the boundary condition on the derivatives of the wave functions at x=0. What are the phase changes for the reflected and transmitted waves?

3. The attempt at a solution

I got the first part of the problem using a boundary condition derived from Newton's second law. And showed that Sin[theta]^2 = R and Cos[theta]^2 = T, where Tan[theta] = m*(omega)/(2*tau*k). I don't know where to start to find the phase changes. I think it has something to do with the ratio of the complex to the real part of the solution that I found in the first part, but again not sure how to go about this.

Last edited: Apr 20, 2007