# Wave Equation After Reflection

1. Apr 9, 2013

### elemis

What do the components of the following equation represent :

http://www.mediafire.com/view/?0we6f9jkw26qi9o

To be clear, this represents a wave of the form Acos(kx-wt) after being reflected off a wall.

I understand that the ∅ represents the phase change of the wave after hitting the wall. The wt is now positive instead of negative because it is travelling in the opposite direction.

Is this a correct description or have I missed something out ?

2. Apr 9, 2013

### Born2bwire

Seems about right. But I would point out that the actual reflected wave would be something like, $A\cos\left(-kx+\omega t + \phi'\right)$ to actually signify that the wave is moving in the negative x direction due to the reflection. One can then use the properties of the cosine to flip the sign of the argument and absorb the sign change in \phi' into \phi.