Post on 06-Jan-2018
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The Behavior of Waves
Reflection
• Reflection – when a wave strikes an object and bounces off of it• All types of waves can be reflected
Law of Reflection• The wave which strikes a surface is called the
incident ray• The wave that bounces off of the surface is
called the reflected ray
Law of Reflection – the angle of incidence is always equal to the angle of reflection
Refraction
• Refraction – the bending of waves caused by a change in its speed as it moves from one medium to another• The greater the change
in its speed, the more the wave bends
Light slows down – bends towards the normal
Light speeds up – bends away from the normal
How does a prism work?
1.) Light waves enter into prism and slow down.
2.) This causes the waves to bend
3.) The different colors of light bend different amounts so the colors are separated
Diffraction
• Diffraction – when an object causes a wave to change direction and bend around it
Diffraction and Wavelength• Amount of diffraction depends on the size of
the object the waves hit and the wavelength of the waves• If the object is smaller than the
wavelength the waves will bend around it• So sound waves which are larger will diffract much better than light waves which are much smaller
Absorption
• Waves can also be absorbed when they strike an object.• Energy is converted into thermal
energy • This is why wearing dark clothes in
the winter months keeps you warmer
Interference
• Interference – when two or more waves combine to form a new wave
Constructive Interference• Constructive interference – when two or
more waves add together• In transverse waves the crests will line up
with one another• In compressional waves the compressions
will line up with one another• The overall effect is to increase the
amplitude (energy) of the wave
Destructive Interference
• Destructive interference – waves subtract from one another when they overlap
Standing Wave
• A standing wave is a special type of wave pattern that forms when waves equal in wavelength and amplitude, but traveling in opposite directions, continuously interfere with each other
• The places where the two waves always cancel are called nodes.