RIGHT PAGE 58 October 25 Focus: Sound and Hearing Objective: Explain the relationship among the rate of vibration, the medium through which vibrations travel, sound and hearing EQ:How does sound travel? HW: story about the eye, unit test Thursday Warm-Up: Review answer questions

WARM UP ANSWER IN COMPLETE SENTENCES 1.What is the difference between a solid, a liquid, and a gas? 2.Describe what the molecules are like in a solid. 3.Describe what the molecules are like in a liquid. 4.Describe what the molecules are like in a gas. 5. What is sound?

Remember What is a solid? A solid is any object where the molecules are TIGHTLY packed very close together.

What is a liquid? A liquid is any object where the molecules are LOOSELY packed.

What is a gas? A gas is any object where the molecules are very far apart and move around easily.

Notes Sound … 1.Is a form of energy produced whenever a body vibrates in a medium. 2.It is transferred by vibrating matter. 3.Vibrations travel from molecule to molecule.

Vibration -Back and forth movement of molecules of matter -For example,

At the end of activity: You will be able to answer this question: Which of the following materials will sound travel through fastest: air, water or wood? Explain your answer.

HUMAN MOLECULES Sound passes from one molecule to another PREDICTION: When molecules are close together, will sound travel faster or slower? When molecules are far apart, will sound travel faster or slower?

HUMAN MOLECULES Sound passes from one molecule to another CONCLUSION: Sound travels fastest through (solid, liquid, gas) because…. Sound travels slowest through (solid, liquid, gas) because….. Molecules close together = easier for sound to move Molecules far apart = harder for sound to move

Now Answer: Which of the following materials will sound travel through fastest: air, water or wood? Explain your answer.

Tuning forks create sound by compressing the air around them. These compressions vibrate air molecules as they travel away from the fork. Sound requires molecules to vibrate. No molecules, no sound.

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Sound travels through different media. We hear sound which usually travels through air. Sound travels through other media as well, such as water and various solids. Sound travels different speeds in different media. Sound typically travels faster in a solid that a liquid and faster in a liquid than a gas. The denser the medium, the faster sound will travel. The higher the temperature, the faster the particles of the medium will move and the faster the particles will carry the sound.

Cornell Notes What is the eardrum? The eardrum is the part of the ear that senses sound waves. Eardrum

Cornell Notes What is the cochlea? The cochlea is the part of your ear that detects vibrations and sends a message to your brain. Eardrum Cochlea Pathway to the Brain

Cornell Notes How are sound waves heard? Sound waves vibrate the eardrum. The vibrations move into the cochlea and then into your brain. Eardrum Cochlea Pathway to the Brain

What is loudness? Loudness is how loud a sound wave is. Loudness comes from the AMPLITUDE of a wave. Cornell Notes How high does it go? How low does it go?

What is pitch? Pitch is the tone of the sound wave. Pitch is determined by the FREQUENCY of a wave. Cornell Notes

Example #1 Which wave is louder? Which wave is softer? A B 1 1 Wave A is louder. Wave B is softer.

Example #2 Which wave is louder? Which wave is softer? A B 2 2 Wave B is louder. Wave A is softer.

Example #3 Which wave is the loudest? Which wave is the softest? A B C 3 3 Wave A is the loudest. Wave C is the softest.

Example #4 Which wave has a higher pitch? Which wave has a lower pitch? A B 4 4 Wave A has a higher pitch. Wave B has a lower pitch.

Example #5 Which wave has a higher pitch? Which wave has a lower pitch? A B 5 5 Wave B has a higher pitch. Wave A has a lower pitch.

Example #6 Which wave has the highest pitch? Which wave has the lowest pitch? C B 6 6 A Wave A has the highest pitch. Wave C has the lowest pitch.

Example #7 Which wave is louder? Which wave has the lowest pitch? B 7 7 A Wave A is louder. Wave B has the lowest pitch.

Example #8 Which wave has the highest pitch? Which wave is softer? B 8 8 A Wave A has the highest pitch. Wave A is softer.

Example #9 Which wave has the highest pitch? Which wave is softer? C B 9 9 Wave B has the highest pitch. Wave C is softer.

Example #10 Which wave has the highest pitch? Which wave is the softest? A B 10 Waves A and B have the same pitch. Wave B is the softest.

Comparing Waves Let’s go back and write comparison statements for each example. Comparison statements answer this question: What is Wave A’s amplitude and pitch compared to Wave B?

Let’s Recap! Look at Size of wave (how high and how low)  Amplitude of Wave  Loudness of Sound Look at the Number of Humps of Wave  Frequency of Wave  Pitch of Sound

Example #4 What is wave A’s loudness and pitch in comparison to wave B? A B 4 4 Wave A is the same loudness as Wave B because the amplitude is the same. Wave A has a higher pitch than Wave B because it has a higher frequency than Wave B.

Example #7 What is wave A’s loudness and pitch in comparison to wave B? B 7 7 A Wave A is louder than Wave B because it has a higher amplitude than Wave B. Wave A has a higher pitch than Wave B because it has a higher frequency than Wave B.

Example #9 What is wave C’s loudness and pitch in comparison to wave B? C B 9 9 Wave C is softer than Wave B because it has a lower amplitude than Wave B. Wave C has a lower pitch than Wave B because it has a lower frequency than Wave B.

Exit Ticket What is Wave A’s loudness and pitch compared to Wave B? Explain your answer! B A