SOUND NOTES LAB STATION PACKET WHAT IS SOUND

SOUND NOTES LAB STATION PACKET

WHAT IS SOUND? WHAT ARE SOUND WAVES? longitudinal • A sound wave is a _______ vibrations wave that is caused by _____ medium and travels through a ______ • Quacking Duck Vibrations • What happens when you drag the wet towel down the string? • Explain why this happens.

compression rarefaction

HOW DO SOUND WAVES TRAVEL? PART 1 • Sound waves travel by disturbing the particles in matter ______________, or a medium. • Most of the sounds you hear travel through air, but sound can also travel water, glass, and metal through __________

STRING TELEPHONE FISHING LINE TELEPHONE • What does sound need in order to be transmitted? • What happens if the string hangs loose? • What happens if you hold the string? • What happens if you connect two or three string telephones together? • Compare what you heard to the string telephone. • Which telephone carried the sound the greatest?

HOW DO SOUND WAVES TRAVEL? PART 2 • Sound must travel through air or some medium other _____ to reach your ears and be detected. • Watch Sound Travel • What happens to the flame? • Why does this happen? • Is there sound in outer space? Explain why or why not.

WHAT AFFECTS PITCH? PART 1 Pitch ______is the highness or lowness of sound. Pitch is determined by the frequency wavelength _______ and ______of sound waves.

WHAT TYPE OF PITCH…HIGH OR LOW? *Low-pitched *High-pitched *Low frequency with long wavelengths *High frequency waves with short wavelengths

PITCH AND FREQUENCY LAB 1. What happens to the frequency and pitch of the sound the ruler makes as you extend more of it off the table edge? The sound became lower so the frequency increased and the pitch was lower. 2. Describe the motion of the ruler. The ruler moved up and down a greater distance when the ruler extended farther than when it was pulled back.

WHAT AFFECTS PITCH? PART 2 What is frequency? Measures how often a waves passes a fixed point! So…how could you increase pitch? Well of course…increase frequency!

WHAT AFFECTS PITCH? PART 2 Hertz (Hz) is the unit used to measure one complete waver (or cycle) per second. The note of middle C on the piano has 262 cycles per second. What is the frequency in Hertz? 262 Hz http: //www. music. vt. edu/musicdictionary/textm/Middle. C. html

WAVE FLASH CARDS A 1 or A 2 • Lower pitch • Long wavelength • Low frequency B 1 or B 2 • higher pitch • short wavelength • high frequency C 1 or C 2 • Lower pitch • Long wavelength • Low frequency

WHAT MAKES A SOUND LOUD? • A measure of how well a sound can be heard is loudness __________ • The measure of how much energy a sound wave intensity or carries is the wave’s ________, amplitude. energy • The more _________ a wave has, the higher the amplitude. louder • The greater the amplitude, the ______ the sound. The smaller the amplitude, the softer _______ the sound.

INVESTIGATE LOUDNESS 1. How did the loudness of the sound compare? The sound was louder at 4 cm than at 1 cm. 2. How is amplitude related to loudness? The greater the amplitude the louder the sound. 3. Challenge: Using what you learned from experimenting with the rubber band, explain why swinging a drumstick harder on a drum would make a louder sound than swinging a drumstick lightly. Swinging a drumstick harder would make a louder sound because the drum skin would vibrate with greater amplitude.

HOW IS LOUDNESS MEASURED? HOW LOUD IS TOO LOUD? • The most common unit used to express decibel loudness is the ________ Comfortable Hearing Under 60 d. B Normal breathing whisper Normal conversation Hearing Damage Begins Damage Zone no more than 15 min. around 120 d. B unprotected for 70 -100 db Hair dryer Vacuum cleaner Garbage disposal traffic Food blender Danger Zone around 125 db thunderclap Airplane takeoff Shotgun firing

Higher pitch lower pitch

What Causes the Doppler Effect? • The change frequency that occurs when the sound source, the observer, or both are moving is called Doppler Effect ___________. • Draw a picture that shows how the Doppler Effect changes the sound of the race car.

• In a few sentences, describe how the sound you hear changes as the racecar moves. The racecar continually sends out sound waves. As it gets closer the sound waves catch up and are spaced closer together. As the racecar moves away the sound waves are still moving towards you; however, the waves are farther apart. • In a few sentences, describe why the frequency of the sound changes and how this change affects the pitch you hear. When the sound waves get closer they are closer together so their frequency is higher which makes the pitch higher. As it moves away the waves are farther apart which means there is a low frequency-low pitch.

WHAT AFFECTS THE SPEED OF SOUND? • Two main factors affect the speed of sound medium temperature • ____________________ steel air A sound wave makes the particles of matter move as it travels, so it moves fastest when particles are close together.

The diver will hear the sound of a boat first because sound waves travel faster in water than in air.

LISTEN TO THIS 1. Does the air or string transmit sound better? Explain. The string transmits sound better than air the or sound was louder. 2. because Does the string the wire transmit sound better? Explain. The wire transmits sound better than the string because the sound was louder. 3. What happens to the energy of a sound wave as it travels through different materials? Different materials absorb different amounts of a sound wave’s energy.

HOW DO SOUND AND MATTER INTERACT? Smooth, hard • Sound waves reflect best off ________ surfaces rough • A ________ wall will absorb sound better than a _________ wall will. And smooth soft ______ materials absorb sound better than hard _______ materials. • Echoes • What materials allowed you to hear the sound in the second tube? • Why are you able to hear the sound in the second tube with these materials? • Why can’t the sound be heard the same with all of the materials?

HOW DO SOUND WAVES INTERACT WITH EACH OTHER? Interference happens when two or more waves • ________ overlap to combine to form one wave • When constructive ________ interference occurs, waves overlap and combine to form a wave with a larger _________ amplitude. This produces a sound that is ______ than before. louder destructive • When ________ interference occurs, waves smaller combine to form a wave with a _________ softer amplitude. This produces a sound that is ______ than before.

INTERFERENCE VIDEOS • What happened to the amplitude of the combined wave when the two waves met? • What would this do to a sound wave? • Draw waves undergoing constructive interference. • What happened to the amplitude of the combined wave when the two waves met? • What would this do to a sound wave? • Draw waves undergoing destructive interference.

SOUND SIMULATION 1. Describe what happens to the wave using the words amplitude, frequency and wavelength as you click from low to medium to high pitch. As the pitch gets higher, the frequency of the wave becomes higher and the wavelength becomes shorter. The amplitude of the wave is not affected. 2. Fill in the blanks: long low Low pitch =_______wavelength and ______frequency short high High pitch = ______ wavelength and ______frequency 3. Describe what happens to the wave using the words amplitude, frequency and wavelength. As the sound gets louder, the amplitude gets higher. Frequency and wavelength are not affected. 4. Fill in the blanks: high low Loud sound = ______ amplitude quiet sound = _____amplitude