WAVES - · PDF fileFrequency –The number of waves that pass a specific ... Wave reflection. Reflection occurs when waves change ... PowerPoint Presentation

WAVES

WAVES

Carries energy from one place to another

Classified by what they move through

1. Mechanical Waves

the energy is transferred by vibrations of medium

(medium = matter, stuff)

ex/ ocean waves move through water

2. Electromagnetic waves (EM Waves)

the energy moves through disturbances in the

electromagnetic field.

a disturbance that transfers energy

WAVE STRUCTURE

CREST (peak)

AMPLITUDE

middle to max peak

WAVELENGTH

TROUGH

WAVE STRUCTURE

Wavelength – the distance between

the same point in two waves.

Amplitude – the distance from the

middle of the wave to the

maximum crest or trough.

Frequency – The number of waves that pass a specific

point each second.

MECHANICAL WAVES

travel through & gradually

lose energy to that

medium

Examples:

water, sound, rope, &

spring waves

Mechanical Media:

water, air, rope, spring

require a medium (the material through which the wave is

moving) to transmit energy

Making a pulse

MECHANICAL WAVES

3 types:

Longitudinal

transverse

surface

http://www.kettering.edu/~drussell/Demos/waves/wavemotion.html

http://physics-animations.com/Physics/English/wlo_tmp.htm

http://physics-animations.com/Physics/English/wlo_tmp.htm

http://physics-animations.com/Physics/English/wtr_tmp.htm


http://physics-animations.com/Physics/English/wwa_tmp.htm


TRANVERSE WAVES

Sideways or up & down

Examples:

S-type earthquake waves

Electromagnetic waves

(ex: light)

Vibration is perpendicular to the direction of

the motion of the wave



LONGITUDINAL WAVES

Back and forth (compression & rarefraction)

Also called compression or pressure wave

Examples:

P-type earthquake waves

Sound waves

Vibration is parallel to the

direction of the motion of the wave

Rarefraction (expansion)

Compression

SURFACE WAVES

Occur at the boundary between two different

mediums

Particles move more the closer they are to the

surface

Example:

Ocean waves

Vibration is circular



CHARACTERISTICS OF WAVES

Amplitude the distance from the

middle of the wave to the

maximum peak.

Frequency ƒ

the number of waves that pass a

specific point each second.

Wavelength the distance between

the same point in two waves.

Velocity vspeed = how fast the wave

travels

v = ƒ

AMPLITUDE

Distance between the “middle & crest” or “middle &

trough”

Gives indication of the

“power” of a wave

Does not affect the

velocity of a wave

Determines strength (earthquake), loudness (sound), or

brightness (electromagnetic wave)

WAVELENGTH Distance between any two

repeating points on a wave

crest-crest, trough-trough,expansion-expansion, compression-compression

Determines what colorswe see; what notes we hear (pitch)

Shorter wavelengths have a higher frequency because the waves aren’t as long

Frequency ƒ

measured in

wavelengths/second

Hertz (Hz) = number of

wavelengths in 1 second

the number of waves that pass a specific point each

second.

VELOCITY v the rate at which the

wave travels

Depends on medium

Mechanical waves travel

faster through dense

mediums

EM Waves are faster

through less dense

mediums

Which is a longitudinal wave, and which is a

transverse wave?


transverse wave?


transverse wave?


transverse wave?


transverse wave?

Earthquakes

Waves traveling through the ground.

P Wave: Primary wave. Moves lateral

Copyright © 2010 Ryan P. Murphy









S Wave: Secondary waves. Stronger and

moves up and down.



moves up and down.



moves up and down.



moves up and down.



moves up and down.


Wave reflection.


Wave reflection.

Reflection occurs when waves change

directions as a result of "bouncing off" a

surface like a mirror.


Wave reflection.





Wave reflection.





Refraction: The bending of a wave when it

enters a medium where its speed is

changed.


An birds must compensate for refraction

when catching fish.


Wave diffraction

A change in the direction of a wave as they

pass through an opening or around an object

in their path

Waves can be absorbed by objects and converted into other types of energy.Light waves can be absorbed by objects and in most cases the energy is converted into heat.

Wave interference.

Two waves can interact with one another, this

interaction is called interference.

Constructive Destructive

Wave interference.


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WAVES - · PDF fileFrequency –The number of waves that pass a specific ... Wave reflection. Reflection occurs when waves change ... PowerPoint Presentation