BellRinger

Bell RingerHow would you describe a wave to someone who had never seen one before?

List 3 different types of waves.

Intro to WavesPhysical ScienceAgendaGuided Notes: Introduction to WavesParts of a WaveTransverse & LongitudinalBoundary InteractionsConstructive & Destructive Interference

What is a Wave?A wave is a disturbance that carries energy from one place to another.A medium is the substance that the wave travels through.

Example 1: When there are waves on the ocean the medium is water.Example 2: When sound travels across the room the medium is air.

WATER is the MEDIUM

AIR is the MEDIUMParts of a WaveThere 3 ways that waves can be measured:

Wavelength: How far apart the waves are.

Amplitude: How tall the wave is.

Frequency: How many waves pass by in a period of time.

AmplitudeCrestWavelengthResting PositionTroughAmplitudeTransverse and Longitudinal Waves A transverse wave vibrates up and down while the wave travels from left to right. These are the normal waves that people usually picture.

A longitudinal wave vibrates left and right as the wave travels from left to right. These waves do not vibrate up and down.

Transverse and Longitudinal Waves

http://www.youtube.com/watch?v=Rbuhdo0AZDU

Boundary ReactionsAs a wave travels, it sometimes moves out of one medium and into anotherThis transition is called a boundary, and it might affect waves in 4 different waysAbsorptionReflectionDiffractionRefractionAbsorptionSoft boundaries absorb waves.This means that the waves energy dies out.Example: Yelling into a pillow.

ReflectionHard boundaries reflect wavesThis means that the wave bounces off of the boundarys surfaceExample: Yelling against a wall

DiffractionCorners diffract wavesThis means the wave bends around the cornerExample: Talking to someone around a corner

RefractionTransparent boundaries refractThis means that the wave bends when it moves into a medium that is faster or slowerExample: Light bends as it passes from air and into the glass of eyeglass lenses

Constructive InterferenceWhen two waves meet, they can be added together if they are in-phase. This means that the high and low points of the wave are matched.When this happens the waves add together in a process called constructive interference.

Destructive InterferenceWhen two waves meet, they can cancel each other if they are out-of-phase. This means that the high and low points of the wave are not matched.When this happens the waves cancel each other in a process called destructive interference.

End of Intro to WavesPhysical Science