Download - The Behavior of Waves
The Behavior of Waves
Wave Speed
Remember: Waves change speed when they encounter a boundary and enter a new medium
Wave Speed
http://www.nisdtx.org/Page/42568Click on the above link and select the video Wave Speed
Reflection
Reflection- when a wave strikes an object and bounces off of it
All types of waves can be reflected Light, sound, ocean, etc. Used by bats and dolphins
All types of waves can be reflected The angle of incidence of a wave is always
equal to the angle of reflection. http://www.acs.psu.edu/drussell/Demos/reflec
t/reflect.html
Reflection
Normal- an imaginary line perpendicular to the reflective surface
Angle of Incidence- the angle formed by the wave striking the surface and the normal
Angle of Reflection- the angle formed by the reflected wave and the normal
Refraction
Why does an object partially in the water look broken or disconnected?
Refraction- the bending of a wave caused by a change in the speed of the wave as it moves from one medium to another Greater change in speed = more bending of
the wave When a wave moves into a medium that slows
it down, the wave is bent toward normal When a wave moves into a medium that
allows it to speed up, the wave is bent away from normal
Refraction
http://www.ps.missouri.edu/rickspage/refract/refraction.html
http://www.physicsclassroom.com/mmedia/waves/ltm.html
http://www.physicsclassroom.com/mmedia/optics/bp.html
Refraction
Diffraction
Diffraction- an object causes a wave to change direction and spread around or through a barrier
Refraction and diffraction both cause bending, but refraction occurs when waves enter a new medium, while diffraction occurs when waves pass around something while still in the same medium
Diffraction
http://www.walter-fendt.de/ph14e/singleslit.htm
http://www.colorado.edu/physics/2000/schroedinger/two-slit2.html
Diffraction
Resonance
Resonance- the ability of an object to vibrate by absorbing energy at its natural frequency
Breaking a glass with sound- resonance: http://www.teachersdomain.org/resources/lsps07/sci/phys/energy/glassbreak/index.html
Tacoma Narrows Bridge
Click the below link to watch the Tacoma Narrows Bridge Video
http://www.nisdtx.org/Page/42568
Breaking Glass
Click on the link below to watch the Breaking Glass video
http://www.nisdtx.org/Page/42568
Interference
http://www.acoustics.salford.ac.uk/feschools/waves/diffract.htm
Interference- the ability of two or more waves to overlap and combine to form a new wave
Waves pass right through each other and continue to travel in their original directions
A new wave exists only while the two original waves continue to overlap
Constructive interference- waves add together
Destructive interference- wave subtract from each other
Interference- green- resulting wave
Interference
http://id.mind.net/~zona/mstm/physics/waves/interference/intrfrnc.html
Standing Waves
Standing waves- a wave pattern that stays in one place
Forms when waves of equal wavelength and amplitude travel in opposite directions- continuously interfering with each other
Nodes- places where the two waves always cancel each other
http://id.mind.net/~zona/mstm/physics/waves/standingWaves/standingWaves1/StandingWaves1.html
http://www.walter-fendt.de/ph14e/stwaverefl.htm
Doppler Effect
Link on the link below to watch the video about the Big Bang Doppler Effect
http://www.nisdtx.org/Page/42568
Doppler Effect
http://www.youtube.com/watch?v=Tn35SB1_NYI
The change in frequency when there is relative motion between an observer of waves and the source of the waves
Doppler with Sound
The Doppler effect-
Change in frequency due to the source or receiver greater the speed the source, greater the Doppler effect Bug swimming Stationary bug
Blue Shift-increase in frequency Red Shift- Decrease in frequency
Doppler Effect
Blue Shift-increase in frequency Red Shift- Decrease in frequency
Red Shift
Click on the link below to watch the video about Red Shift
http://www.nisdtx.org/Page/42568
Bow waves
V-shaped pattern made by overlapping crest
Shock Waves
Produced by supersonic aircraft, three-dimensional cone shaped
Sonic boom – sharp crack heard when conical shell of compressed air that sweeps behind a supersonic aircraft reaches listeners on the ground below.
Supersonic
Subsonic - slower than the speed of sound Supersonic- faster than the speed of sound