Wave+Interactions

__ **Wave Interactions** __ __**The Doppler** **Effect-**__ an apparent change in __pitch__ (frequency) due to the __motion__ towards or away from an object Examples of the doppler efeect in real life is an ambulance, airplane, racecar, train, etc.

This video helps to visually explain the Doppler Effect... media type="youtube" key="iN3fO5l4Rww" height="344" width="425"


 * __4 Types of Wave Interactions__

1. __Reflection-__** the __bounce__ off of an object In a Reflection, shown in this picture above, the red wave is called the incident wave, or the original wave. The blue wave, or the reflected wave is the outcome of the wave, when reflected through water, or a mirror. This picture demonstrates the first type of wave interaction.

2. __**Refraction-**__ the __bending__ of a wave due to a changing medium. This definition makes this seem very complicated... but perhaps a picture would help you understand better.

By observing this picture, you can see that the pencil that was put into the cup seems as if it is broken or bent. This is because the pencil has been put into two different mediums... Water, and Air.

3. **__Diffraction-__** the __bending__ of waves due to an object or hole. One example of diffraction is as follows. Have you ever looked at car lights, and it seems to be coming from one main point but ends up looking like the sun? Is it going out in all drections? This is because it is so bright that you needed to squint. Yes, squinting causes a type of wave interaction. Diffraction can also be explained in many other ways, for example, a river... This also is an example of diffraction because the waves are made to bend in a different direction in order to go around the rocks.

4. **__Interference-__** two waves __colliding__



Line A represents interference when two waves of opposite heights collide. This cause the wave to become flat. A real life example of this is when it starts to rain in a lake, and two different rain drop ripples collide in the water. For the tiny bit of time that they hit, it becomes flat because the cancel each other out. Line B represents interference when to waves of the same height collide. For example, in the ocean, when one wave is crashing into the shore, and the other wave is going back into the ocean, they have no choice but to collide. For the little amount of time that these waves hit, they become twice as big.