CHAPTER 20

THE ENERGY OF WAVES

Waves - _________________________________________________________**As the wave travels away from its source, energy moves through a ___________but the ________________ does not move with the energy. The particles of thematerial move __________________ to the direction of the wave. The wave uses_______________ to do work on everything in its path.

Energy transfer:1. Through a medium. A medium is ______________________________________________________________________________________Waves that require a medium are know as ________________________and include: 1. ___________________

2. __________________________________3. __________________________________

2. Waves that do not require a medium are know as ___________________ _____________ and include:

1. __________________________2. __________________________3. __________________________4. __________________________

These waves do not require a medium but can travel through substancessuch as ___________, _______________, and ______________.

any disturbance that transmits energy through matter or space

materialmaterial

perpendicularenergy

a substance through whicha wave can travel, which can be solid, liquid, or gas

mechanical wavesSound wavesWater waves (ocean)

Seismic waves (earthquakes)electromagnetic

wavesvisible lightTV and radio signals

X-raysmicrowaves

air water glass

Types of Waves1. Transverse Waves - _____________________________________________________________________________________________________________________________________________________________________Example: a wave moving on a ______________ All electromagnetic waves

are classified as____________________.

waves in which the particles vibrate with an up and down motion, perpendicular to the directionthe wave is traveling.

rope

crest

trough

transverse waves

2. Longitudinal Waves - _____________________________________________________________________________________________________Example: a slinky or spring

the particles of the medium vibrate back and forthalong the path the wave travels

wavelength

amplitude

Sound waves are examplesof ______________________waves.

longitudinal

3. Combinations of Waves - ____________________________________________________________________________________________________________________________________________________________________

a longitudinal and transverse wave can combineto form a surface wave at or near the boundaryof 2 media.

Example: ____________________________Ocean waves

Properties of Waves:1. Amplitude - ______________________________________________________________________The larger the amplitude, the ____________ the waveand the more ____________ it carries.

the maximum distance the wavevibrates from its rest position

tallerenergy

2. Wavelength - ________________________________________________________________________________________________________________________________________________________________________________

the distance between 2 adjacent crests or compressionsin a series of waves, or from a point on one wave to acorresponding point on the next wave.

3. Frequency - _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________The higher the frequency, the more ___________ pass by per _____________,and the higher the ______________.

the number of waves produced in a given amountof time. Do this by counting the number of crests ortroughs (or compressions or rarefractions) that passby a certain point in one second. The unit is hertzwhere 1 Hz = 1 /second.

waves secondenergy

4. Wave speed - _________________________________________________

When v = _________________, λ = ____________________, and f = _____________________, you can use the following equation:

v = ____ x ______What is the frequency of a wave if it has a speed of 12 cm/s ad a wavelengthof 3 cm? v = λ x f

the speed at which a wave travels (distance / time)

12 cm/s = 3 cm x f______ _____3 cm 3 cm

4/s = f4 Hz = f

A wave has a frequency of 5 Hz and a wave speed of 18 m/s. What is itswavelength? v = λ x f

18 m/s = λ x 5 Hz_____ ____5 Hz 5 Hz

3.6 m = λ

wave speed wavelengthfrequency

λ f

Wave Interactions1. Reflection - __________________________________________________

Examples: Reflected light makes the ____________ shine.Reflected sound is called an ____________.

when a wave bounces back after striking a barriermoonecho

2. Refraction - __________________________________________________________________________________

the bending of a wave as it passesat an angle from one medium to another

3. Diffraction - ____________________________________________________The amount of diffraction depends on the _________________ and _________of the barrier or opening the wave encounters. _____________ waves arediffracted more than _____________ waves because they have a ____________wavelength.

The bending of waves around a barrier or through an openingwavelength size

Soundlight larger

4. Interference - __________________________________________________A. Constructive Interference - ________________________________________________________________________________________

B. Destructive Interference - _________________________________________________________________________________________

the result of 2 or more waves overlapping This occurs when the crests of one wave overlap the crests of another wave or waves

This occurs when the crest of one wave and the troughs of another wave overlap.

C. Standing waves - _______________________________________________________________________________________________________________________________________________________________________________________________________________

These are waves that form a stationary pattern in which portions of the wave are at the rest positiondue to total destructive interference and other portions have a large amplitude due to constructive interference.

D. Resonance - _______________________________________________________________________________________________________________________________This happens because the secondobject absorbed ______________from the original vibrating object.

When an objectvibrating at a frequency producinga standing wave causes anotherobject to vibrate

energy

CHAPTER 20

THE ENERGY OF WAVES

Waves - _________________________________________________________**As the wave travels away from its source, energy moves through a ___________but the ________________ does not move with the energy. The particles of thematerial move __________________ to the direction of the wave. The wave uses_______________ to do work on everything in its path.

Energy transfer:1. Through a medium. A medium is ______________________________________________________________________________________Waves that require a medium are know as ________________________and include: 1. ___________________

2. __________________________________3. __________________________________

2. Waves that do not require a medium are know as ___________________ _____________ and include:

1. __________________________2. __________________________3. __________________________4. __________________________

These waves do not require a medium but can travel through substancessuch as ___________, _______________, and ______________.

Types of Waves1. Transverse Waves - _____________________________________________________________________________________________________________________________________________________________________Example: a wave moving on a ______________ All electromagnetic waves

are classified as____________________.

2. Longitudinal Waves - _____________________________________________________________________________________________________Example: a slinky or spring

Sound waves are examplesof ______________________waves.

3. Combinations of Waves - ____________________________________________________________________________________________________________________________________________________________________

Example: ____________________________

Properties of Waves:1. Amplitude - ______________________________________________________________________The larger the amplitude, the ____________ the waveand the more ____________ it carries.

2. Wavelength - ________________________________________________________________________________________________________________________________________________________________________________

3. Frequency - _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________The higher the frequency, the more ___________ pass by per _____________,and the higher the ______________.

4. Wave speed - _________________________________________________

When v = _________________, λ = ____________________, and f = _____________________, you can use the following equation:

v = ____ x ______What is the frequency of a wave if it has a speed of 12 cm/s ad a wavelengthof 3 cm? v = λ x f

A wave has a frequency of 5 Hz and a wave speed of 18 m/s. What is itswavelength? v = λ x f

Wave Interactions1. Reflection - __________________________________________________

Examples: Reflected light makes the ____________ shine.Reflected sound is called an ____________.

2. Refraction - __________________________________________________________________________________

3. Diffraction - ____________________________________________________The amount of diffraction depends on the _________________ and _________of the barrier or opening the wave encounters. _____________ waves arediffracted more than _____________ waves because they have a ____________wavelength.

4. Interference - __________________________________________________A. Constructive Interference - ________________________________________________________________________________________

B. Destructive Interference - _________________________________________________________________________________________

.

C. Standing waves - _______________________________________________________________________________________________________________________________________________________________________________________________________________

D. Resonance - _______________________________________________________________________________________________________________________________This happens because the secondobject absorbed ______________from the original vibrating object.