What is a Wave?What is a Wave?

Chapter 10 Section 1Chapter 10 Section 1Glencoe Pages 288-293Glencoe Pages 288-293

I. Types of waves I. Types of waves A. What is a wave?A. What is a wave?

1. Wave – a disturbance that carries 1. Wave – a disturbance that carries energyenergy

through matter or spacethrough matter or space

the matter moves very littlethe matter moves very little

the energy movesthe energy moves

Most waves travel through a Most waves travel through a mediummedium2. Most waves travel through a medium2. Most waves travel through a medium

a. medium – matter through a. medium – matter through which awhich a

wave travelswave travels

ripples in a pond move through ripples in a pond move through waterwater

sound waves travel through the airsound waves travel through the air

Mechanical wavesMechanical waves

b. Mechanical waves – waves that b. Mechanical waves – waves that require arequire a

medium to travel medium to travel

almost all waves are of this almost all waves are of this typetype

Electromagnetic wavesElectromagnetic waves

c. Electromagnetic waves – waves caused by c. Electromagnetic waves – waves caused by electric and magnetic fields that do not electric and magnetic fields that do not require a mediumrequire a medium

Electromagnetic spectrum of waves,Electromagnetic spectrum of waves,

consisting of: consisting of: Radio waves, Microwaves, Infrared waves, Radio waves, Microwaves, Infrared waves,

Visible light, Ultraviolet waves, X-rays, and Visible light, Ultraviolet waves, X-rays, and Gamma rays Gamma rays

Electromagnetic wavesElectromagnetic waves

Electromagnetic wavesElectromagnetic waves

Electromagnetic wavesElectromagnetic waves

Wave EnergyWave Energy3. Waves transfer energy3. Waves transfer energy energy is the ability to do workenergy is the ability to do work waves have energy therefore waves can do waves have energy therefore waves can do

workworkexample:example: water waves on a boatwater waves on a boat

Wave EnergyWave Energy

Example: light waves on the eyesExample: light waves on the eyes

Wave EnergyWave Energy

Example: sound waves on your Example: sound waves on your eardrumeardrum

*Bigger waves carry more energy*Bigger waves carry more energy

Wave EnergyWave Energy4. Energy may spread out as a wave travels4. Energy may spread out as a wave travels

- sound waves, ripples in a pond move out - sound waves, ripples in a pond move out

in circular patterns called wave fronts,in circular patterns called wave fronts,

and get bigger farther from the sourceand get bigger farther from the source

and the energy spreads out along theand the energy spreads out along the

entire wave frontentire wave front

B. Vibrations and wavesB. Vibrations and waves

1. Most waves are 1. Most waves are created by a created by a vibratingvibrating

objectobject

2. Vibrations involve a 2. Vibrations involve a

transformation oftransformation of

energy, generallyenergy, generally

between potentialbetween potential

and kineticand kinetic

C. Transverse and longitudinal C. Transverse and longitudinal waveswaves

1. Particles in a medium can vibrate 1. Particles in a medium can vibrate upup

and down or back and forthand down or back and forth

2. Waves are classified by the 2. Waves are classified by the direction ofdirection of

particle movementparticle movement

Transverse and longitudinal Transverse and longitudinal waveswaves

3. Transverse waves – waves causing the 3. Transverse waves – waves causing the particles of the medium to vibrate particles of the medium to vibrate perpendicular to the direction the wave is perpendicular to the direction the wave is traveling.traveling.Ex. Crowd doing the wave, light wavesEx. Crowd doing the wave, light waves

Transverse and longitudinal Transverse and longitudinal waveswaves

4. Longitudinal waves – waves causing the medium 4. Longitudinal waves – waves causing the medium particles to move parallel to the wave’s direction of particles to move parallel to the wave’s direction of traveltravel

squeezing together (compression) squeezing together (compression) spreading apart (rarefactions)spreading apart (rarefactions)

ex. Sound wavesex. Sound waves

Surface wavesSurface waves5. Surface waves – occur at 5. Surface waves – occur at

boundaries between different boundaries between different mediumsmediums

air and waterair and water

- these waves move both in a - these waves move both in a transverse and a longitudinal transverse and a longitudinal way.way.