The Behavior of Waves

Wave Speed Remember: Waves change speed when they encounter a boundary and enter a new medium

Wave Speed Click 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. t/reflect.html 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 efraction.html efraction.html aves/ltm.html aves/ltm.html tics/bp.html tics/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 fendt.de/ph14e/singleslit.htm fendt.de/ph14e/singleslit.htm dinger/two-slit2.html dinger/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: /lsps07/sci/phys/energy/glassbreak/index. html /lsps07/sci/phys/energy/glassbreak/index. html

Tacoma Narrows Bridge Click the below link to watch the Tacoma Narrows Bridge Video

Breaking Glass Click on the link below to watch the Breaking Glass video

Interference waves/diffract.htm 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

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 standingWaves/standingWaves1/StandingWa ves1.html standingWaves/standingWaves1/StandingWa ves1.html fendt.de/ph14e/stwaverefl.htm fendt.de/ph14e/stwaverefl.htm

Doppler Effect Link on the link below to watch the video about the Big Bang Doppler Effect

Doppler Effect 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 swimmingStationary 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

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