Rflection of a wave

[koveras00]

I realized that when a wave reflects(bounces) off a hard surface, it nudergoes a phase change of 'pie'. But i cannot visualize it. Anyone can help me?? Thanks alot....

[fee]

The page
http://www.kettering.edu/~drussell/Demos/reflect/reflect.html
is the best that I have come across for visualizations of phase changes upon reflection.
See also
http://www.physicsclassroom.com/mmedia/waves/ltm.html

[perezelen]

If a linear object attached to an oscillator bobs back and forth within the water, it becomes a source of straight waves. These straight waves have alternating crests and troughs. These waves will travel through the water until they encounter an obstacle - such as the wall of the tank or an object placed within the water.