WAVES, SOUND, AND LIGHT

Chapter 24

WAVES CARRY ENERGY, BUT NOT MATTER Wave

A disturbance that moves through matter or space

Carry Energy from one place to another

TYPES OF WAVES Mechanical

Transverse Particles move back and

forth at right angles (like a jump rope)

Compressional Particles move back and

forth along the same direction (like a spring)

Electromagnetic Move through matter

or space Light, Radio Waves, X-

Rays

PROPERTIES OF WAVES Wavelength

Distance between 2 points on a wave

Frequency The number of

wavelengths per second

Amplitude Transverse

Half the distance between the crest and trough of a wave

AMPLITUDE AND ENERGYThe more energy a wave carries, the larger its amplitude

WAVES CAN CHANGE DIRECTION Law of Reflection

The angle of the reflection always equals the angle of incidence (the normal)

RefractionThe change in

direction of a wave when it changes speed

WAVES CAN CHANGE DIRECTION Diffraction

The bending of waves around an object

Depends on the size of the object the wave encounters

SOUND WAVES Compressional

Waves Can only travel

though matter Transferred by

the collision between the particles the waves are traveling through

SPEED OF SOUND Sound waves

travel faster through solids and liquids

Speed of Sound increases as temperature increases

LOUDNESS OF SOUND Intensity

Amount of energy carried by a wave

Greater amplitude = Greater intensity

Measured in decibels (dB)

FREQUENCY AND PITCH Frequency

The number of waves per second

Measured in hertz (Hz) Pitch

The human perception of the frequency of sound

Low frequencies=low pitch

High frequencies=high pitch

HEARING AND THE EAR Outer Ear

Visible part of the ear Shaped like a funnel

Middle Ear Sound Amplifier Contains the

hammer, anvil, and stirrup

Inner Ear Contains the cochlea

Filled with fluid Lined with cilia (hair

like cells)

REFLECTION OF SOUND Reverberation

Repeated echoes Echolocation

The process of locating objects by bouncing short, high-frequency sound waves towards a certain area

LIGHT Electromagnetic

WavesWaves that can

travel through matter or through empty space

Speed of Light300,000 km/s

THE ELECTROMAGNETIC SPECTRUM The complete range of electromagnetic

wave frequencies and wavelengths Contains radio waves, microwaves,

infrared waves, ultraviolet waves, x-rays, and gamma waves

All are the same type of wave. Differ only in frequency, wavelength, and energy

THE ELECTROMAGNETIC SPECTRUM

THE VISIBLE SPECTRUM The color of light depends on the

wavelength Violet has the shortest wavelength Red has the longest wavelength White is the combination of all colors In Order from longest to shortest:

Red, Orange, Yellow, Green, Blue, Indigo, Violet

THE VISIBLE SPECTRUM