Sound Lab

Monday March 12th, 2012

What makes sound?

What you need to write on your paper:

Lab Station #1: Drumming

Lab Station #2: Your throat

Lab Station #3: Tuning fork

Lab Station #4: Rubber band strung

Lab Station #5: Buzzer

Lab Station #6: Steel yardstick

Lab Directions:

Every station will have a bright green paper with simple directions on what to do.

Make sure everyone takes a turn, then discuss and answer the question you copied from the previous slide

Sound Lab

1.) Describe what you hear, feel, and see.2.) Did the sound ever change and how did you make it change?3) What are your overall conclusions about the sound at this station?

Questions:

Sound Lab cont’Station # 1- Drumming

Question 1

Question 2

Question 3

Warm up: unscramble the words below

Example: vawe = wave

*All the words have to do with what we are studying

dosun

cipth

tbiiranvo

Olssdenu

rae

Happy Monday March 19th, 2012

Warm Up- Respond to the

following questions in your lab

• What happens to sound waves when they reach a wall or other solid, flat object?

• Explain why, based on the behavior of sound waves, a classroom with a tile floor is louder than a library that is carpeted.

• Why you see lightning before you hear thunder during storms?

Sound VibrationIs a wave that vibrates

particles of matterA rapid back and forth movement

Sound Wave Notes

So then, Why is there not sound in space?

Space is a vacuum, which means empty space or very few particles.

Sound has to vibrate matter or a medium in order to produce sound.

In space there is no ‘air’ or medium for the wave to vibrate, thus no sound can be produced.

How do we produce sound?

We use our muscles in our body

to push air up from your lungs

through an narrow passage through

the vocal cords, which are actually

folds!

The force of air causes them to vibrate

That action produces sound waves!

From 42sec to 2:58

http://www.youtube.com/watch?v=wYeauSxXSBA&feature=related

How does our ears hear sound waves?

Vibrations travel though the ear canal

Then the sound waves vibrate the eardrum, which moves the 3 bones in the ear called hammer, anvil, and stirrup

Continued- How do our ears hear

sound waves?

The eardrum vibrating causes the three bones in the ear to vibrate, which is detected by the cochlea

The cochlea has millions of little hairs inside ear fluid the move with the vibrations, then nerves send messages for the brain to decipher.

Do ear cup example

http://www.youtube.com/watch?v=tkPj4IGbmQQ&feature=related

What affects the speed of sound?

Temperature and medium effects the speed of sound.

Speed of Sound in Different Mediums

If the mediums are all 20 degree C then the following is true . . .

In Air-Gas sound waves travel at 344 m/s

In Water-Liquid 1,400 m/s

In Steel-Solid 5,000 m/s

Speed of Sound in Different Temperatures

If you are in the desert and in it 115 degrees F sound will travel faster, then if you are in the arctic and it is -20 degrees F!

Why?

At higher temperatures particles move faster. So if sound waves push against the already fast moving particles, then it will quickly pass through and vibrate the already fast moving particles.

Hall way example

Frequency

A given number of waves in specific amount of time, which determines the pitch.

The pitch is a characteristic of high and low sounds.

Frequency is measured in hertz. (hz)

The Doppler Effect

The Doppler Effect is a change in the perceived pitch when the source of the noise is moving.

So to Further Explain: All waves, light and sound, travel out from the source, but when the source is moving the waves get bunched closed together making a higher frequency/pitch and the waves trailing behind become spread out making a lower pitch/frequency.

http://www.youtube.com/watch?v=Kg9F5pN5tlI

Amplitude

Amplitude determines intensity, which is just how loud sound is.

Intensity or amplitude of sound is measured in decibels (dB).

Decibels (dB)

Examples:

10 dB Leaves Rustling

30 dB Whisper

60 dB Dog Barking

90 dB Motorcycle

140 dB Firecrackers

1. What is sound?

2. How many bones are in the ear?

3. What part of the ear has millions of hairs and fluid in it?

4. What are the two main parts of the body that help to produce sound?

5. Is it easier for sound waves to pass through a solid or a liquid? Why?

6. Is it easier for sound waves to pass through a hot gas or a cool gas? Why?

7. Frequency determines the __________ of the sound and is measured in ______________.

8. Explain the Doppler Effect.

9. What is an example of the Doppler effect?

Pop Quiz : D*Don’t Worry you can use your notes.

Review Practice Questions

Question 1-

Which do you hear 1st . . . .

1- Your postman saying “Hi” from 20ft away

2- A car crash 500 meters away

3- An air plane taking off 10,000 meters away

Review Practice QuestionsQuestion 2-

Why can you see something happen then hear it? For example a tree far off falls then a second later you hear it.

1-The sound travels in many directions at once

2-Sound is a wave

3-Sound faster than light

4-That is just how much time the sound takes to reach the listener

Review Practice QuestionsQuestion 3-

How does cupping your hand to your ear help you hear?

1-Sound waves move through you hand

2-The hand reflects the more sound waves into the ear

3- More sound waves are refracted into the ear

4-There is more air for the sound waves to more through

Review Practice QuestionsQuestion 4-

What effects the intensity of the sound most? Pick 2

1-Temprature of medium

2-Length of medium

3- Material of medium

4-Color of medium

5-Transparcy of the medium

Review Practice QuestionsQuestion 5-

Fill in the blanks: ________________ determines the pitch and ____________________ determines the volume/loudness.

1-Wavelength:Intensity

2-Frequency:Wavelength

3-Intensity:Frequency

4-Frequency: Intensity