Wave Notes- Interactions

·  There are 4 types of wave interactions:

o  reflection

o  refraction

o  diffraction

o  interference

·  reflection happens when a wave bounces back after hitting a barrier it cannot go through

·  All waves can be reflected:

o  light waves reflecting off an object allow you to see that object.

§  mirror

o  A reflected sound wave is called an echo

·  The Law of Reflection states that the angle of incidence equals the angle of reflection

Angle of Incidence
the angle between the incoming wave and the imaginary vertical line. / Angle of Reflection
the angle between the reflected wave and the imaginary line.

·  Refraction is the bending of a wave as the wave pass from one medium to another at an angle.

·  When a wave moves from one medium to another, the wave’s speed changes.

o  As a result, the wave bends and travels in a new direction

·  Label which part of the wave is traveling at a faster speed:

·  Diffraction is the bending of waves around a barrier or through an opening.

·  Diffraction depends on 2 things:

o  wavelength

o  size of the barrier or opening

·  interference is the result of two or more waves overlapping.

·  2 types of interference:

o  constructive

o  destructive

·  constructive interference occurs when the crest and trough of 1 wave overlap with the crest and trough of another wave.

o  The result is a new wave that has a higher amplitude than the original waves had

·  destructive interference occurs when the crest of 1 wave and the trough of another wave overlap.

o  The new wave will have smaller amplitude than the original waves had.

o  When the waves involved in destructive interference have the same amplitude and meet each other at just the right time, the result is no wave at all.

·  Label each as either constructive or destructive interference: