Waves Ch 11 sect 1

Waves A wave is a repeating disturbance that transfers energy  An easy example to visualize a wave is to think of a rock dropping into water  Examples of different waves are light waves, sound waves, microwaves

Waves (continued) Waves only transfer energy, they do not transfer matter  Example-When you are sitting in a boat and another boat goes by the wake passes underneath you but it does not cause you to go with it. Waves only travel while they have energy

Mechanical Waves A mechanical wave is a wave that has to have a medium to travel through  The medium is anything that the wave can transfer energy through  The medium can be solid, liquid, or gas

Types of Waves  There are 2 major types of waves that you will learn about 1. Compressional Wave-The medium moves in the same direction as the energy  Longitudinal Wave Longitudinal Wave 2. Transverse Wave-The medium moves at a 90 degree angle to the energy  Transverse Wave Transverse Wave

Compressional Wave A compressional wave works on a series of collisions  Release of energy leads to movement of particles which leads to collision of particles which leads to the transfer of energy  Sound waves are examples of compressional waves

Parts of a Compressional- Longitudinal wave A compressional wave is made up of 2 different parts 1.Compression-The part of the wave that is pushed or compressed together More compression = more energy in the wave 2.Rarefaction-The part of the wave that is spread out compressional images

Transverse Wave A transverse wave is a line with peaks and valleys One example of a transverse wave is light Light does not need a medium to travel therefore it is not a mechanical wave

Parts of a Transverse Wave  A transverse wave is made up of two parts 1. Crest-the crest is the area above the midpoint of the wave  The higher the crest the more energy a wave has 2. Trough-The trough is the area below the midpoint of the wave Transverse Image

Sound Waves Sound is an example of a compressional wave Sound is an example of a compressional wave Made up of compressionsMade up of compressions Made up of rarefactionsMade up of rarefactions Can move through different mediumsCan move through different mediums

Behavior of Sound Waves Just like all waves the more NRG it has the further it will travel Just like all waves the more NRG it has the further it will travel Just like light waves the frequency will affect the outcome Just like light waves the frequency will affect the outcome High frequency = high pitchHigh frequency = high pitch high pitch sound high pitch sound high pitch sound high pitch sound Low frequency = low pitchLow frequency = low pitch

Speed of Sound Speed of sound through air is about 769 miles per hour Speed of sound through air is about 769 miles per hour.21 miles per second.21 miles per second

Doppler Effect  Doppler effect is the change in wavelengths do to movement Ex.- if you are sitting at the train tracks and a train is coming it will sound different when it is approaching compared to once it passes Doppler effect

Wave Interference  There are two types of wave interference that you will need to know for the test 1.Constructive interference-The waves come together to increase in size  Compression + Compression, Crest + Crest 2.Destructive interference-The waves come together and cancel each other out  Compression + Rarefaction, Crest + Trough