Chapter 2

Take a guess at the sounds clips……

1.

2.

Crest

Trough

Compression Compression Compression

Trough

Crest

Wavelength

Frequency

What is sound?

Sound is a disturbance that travels through a medium as a longitudinal wave

Seeing Sound Waves- watch how the particles move when the sound changes…pretty cool

~ It carries energy through a medium.

~ Most common medium for sound is AIR

http://www.teachertube.com/viewVideo.php?title=Sound_Education&video_id=21129

Whenever you speak or sing you force air through your lungs up through your voice box.

Sing…. Pick a song and sing together… Hold on to your larynx and feel the different vibrations from singing loudly then softly

SOUND DOES NOT TRAVEL THROUGH OUTER SPACE…..WHY?

Sound only travels through a medium and there are no mediums in space!!

*When sound hits a barrier some of the waves pass through…..

* The speed of sound depends on the elasticity, density, and temperature of the medium

Look at the chart on page 42….

Does sound travel faster through gases, liquids, or solids?

Elasticity

The ability of a material to bounce back after being disturbed

If a medium is very elastic, the particles easily go back into their original position.

Solids- Most elastic- since solids are close together the material bounce back and forth quickly

Liquids- not very elastic

Gas- very inelastic and poorest transmitters of sound

Density•How much matter, or mass, there is in a given amount of space, or volume

•Sound travels more slowly in denser mediums

Bread activity

Less Dense More Dense

Slower at low temp

Faster at high temp

Vocabulary 1-10 (First Page)

Have a great day!!

http://www.brainpop.com/science/energy/sound/

What is sound intensity?

Sound intensity is the energy that the sound wave possesses. The greater the intensity of sound the farther the sound will travel and the louder the sound will appear.

Loudness is very closely related to intensity. Loudness is the human perception of the sound intensity. The unit for loudness is decibels.

Loudness in Decibels

Whisper 20 decibels Plane 120 decibels

Conversation 60 decibels Siren 100 decibels

Moving Towardsource

Moving Towardobserver Observed Frequency

Is higher

Moving Away from

observer

Moving Away from

sourceObserved FrequencyIs lower

Moving Away from

observerObserver

At restObserved FrequencyIs lower

Moving Towardobserver

ObserverAt restObserved Frequency

Is higher