CHAPTER 11LESSON 1

SOUND AND WAVESJulliana Inding

Josh PaculbaSteven GoPiolo Diaz

Dridgely Dy

WHAT ARE WAVES?A wave is a disturbance that

transfers energy from one point to another. The movement of particles by a wave is called

vibration. There are two types of waves: transverse waves and

compressional waves.

TYPES OF WAVESWhen a transverse wave

travels through a medium, matter moves up and down as the wave

travels through it.When a compressional wave travels, matter moves back and

forth as the wave travels through it.

HOW CAN YOU MEASURE WAVES?Wavelength is the distance

between wave crests or troughs.

Frequency is a measure of how many wave crests or troughs

pass a given point in one unit of time, such as a second.Amplitude, the height of the

wave from its tough or crest to its midpoint, is a measure of the

wave’s intensity.

FREQUENCY AND SPEED OF WAVES

Frequency is measured in hertz (Hz) the number of waves per

second. Hertz means “cycles per second” with respect to frequency.

Speed describes how fast something travels in a specific amount of time.

FACTORS THAT AFFECT SPEED

Wave speed is affected by different factors of its medium. The depth of water affects

speed of ocean waves. The deeper the water is, the faster the waves travel. In some

waves, the distance between particles affect speed.

Sound waves move faster through solids, slower through liquids and

slowest through gases.

HOW DOES SOUND TRAVEL?

Sound travels by means of sound waves. The energy causes then to vibrate in a wave like pattern.

Sound travels through air and liquids. Sound is harder to hear

through liquids and solid objects. The more dense an object is the less sound will make it through.

REFLECTED SOUND

An echo is a reflected sound wave.

Reflection refers to how waves bounce off objects and change

their direction of travel.

REFRACTED SOUND

Refraction occurs when the direction of a wave changes because of change in medium.

ABSORBING SOUND WAVES

The material a sound wave strikes affects how the sound wave

moves. A material that absorbs sound well does not reflect sound

waves.

THE DOPPLER EFFECT

A sound’s pitch seems to change if its source or listener is moving. This is called the doppler effect

VOLUME OF A SOUNDThe difference in the loudness of a

sound is called volume. The amount of energy, or intensity, of the sound wave determines the volume of a sound. The volume of a sound is

measured in decibels (dB).

INTERFERENCEConstructive interference is

the combined sound waves of the stereos would produce a louder

sound than from one stereo alone.

Destructive interference is the sound waves together have a

lower amplitude than the sound made by one sound source alone.

HOW DO WE HEAR MUSIC?The difference among sound of the

same pitch and amplitude in various instruments is called

sound quality.As sound waves travel, they

transfer energy and as they pass through your ear canal, they

cause the ear drum to vibrate that nerve cells inside the ears are stimulated. The vibrations

are converted to nerve impulses which the brain recognize.

Music- A combination of sounds that a

listener finds pleasing

Noise- A combination of sounds that a

listener finds unpleasant

Rhythm- A mathematical sounds’ structure of

tones and silence