Chapter 26 ReviewChapter 26 Review

Applied PhysicsApplied Physics

VocabularyVocabulary

Your vocabulary Your vocabulary assessment will assessment will consist of matching consist of matching words and definitions.words and definitions.

Please study the Please study the vocabulary from your vocabulary from your packet.packet.

BeatsBeats CompressionCompression Forced VibrationForced Vibration InfrasonicInfrasonic Natural FrequencyNatural Frequency PitchPitch RarefactionRarefaction ResonanceResonance UltrasonicUltrasonic

Concepts (Basic Sound)Concepts (Basic Sound)Sound forms ______________ waves.Sound forms ______________ waves.Sound originates from _____________.Sound originates from _____________.Sound waves require _____________ in Sound waves require _____________ in

order to travel.order to travel.Sound travels better in ___________ and Sound travels better in ___________ and

____________________Know the parts of a sound wave.Know the parts of a sound wave.

Concepts (Interference)Concepts (Interference)Two Sound waves can _____________ Two Sound waves can _____________

with each other.with each other.____________ interference occurs when ____________ interference occurs when

sounds amplify each other.sounds amplify each other.____________ interference occurs when ____________ interference occurs when

sounds deaden each other.sounds deaden each other.____________ occurs when sounds ____________ occurs when sounds

periodically get louder and softer.periodically get louder and softer.

Concepts (Interference)Concepts (Interference) Identify either constructive or destructive Identify either constructive or destructive

interference as a result.interference as a result.

Concepts (Interference)Concepts (Interference)Most objects have a frequency in which Most objects have a frequency in which

they vibrate with minimal energy loss. they vibrate with minimal energy loss. This is called the ___________ frequency.This is called the ___________ frequency.

An object driven at this frequency will An object driven at this frequency will experience an ___________ in sound. experience an ___________ in sound.

The phenomenon mentioned above is The phenomenon mentioned above is called __________.called __________.

Concepts (Frequencies)Concepts (Frequencies)____________ directly relates to the ____________ directly relates to the

frequency of sound.frequency of sound.Humans can hear frequencies between Humans can hear frequencies between

_______ and _______ Hz._______ and _______ Hz.Sounds below that threshold are called Sounds below that threshold are called

___________.___________.Sounds above that threshold are called Sounds above that threshold are called

___________.___________.

Concepts (Sound Intensity)Concepts (Sound Intensity)__________ is our impression of the __________ is our impression of the

intensity of sound.intensity of sound.Scientists use the __________ (dB) scale Scientists use the __________ (dB) scale

to measure intensity level.to measure intensity level.The scale is different because an increase The scale is different because an increase

of 10dB from any point is actually a of 10dB from any point is actually a multiplication by ____multiplication by ____

How many times louder is 50dB than How many times louder is 50dB than 20dB?20dB?

Concepts (Sound Speed)Concepts (Sound Speed)The speed of sound in air at room temp is The speed of sound in air at room temp is

______ m/s, as opposed to ____ m/s at ______ m/s, as opposed to ____ m/s at 00°°C.C.

Speed of sound is affected by Speed of sound is affected by __________ and ___________, not __________ and ___________, not __________ and ___________.__________ and ___________.

Sound travels ____ times faster in water Sound travels ____ times faster in water and ____ times faster in steel.and ____ times faster in steel.

Sound ProblemsSound ProblemsYou will need to know how to use the You will need to know how to use the

following equations:following equations:

Recall: the quantities are as follows:Recall: the quantities are as follows:Speed (variable ____ and units ____)Speed (variable ____ and units ____)Frequency (variable ____ and units ____)Frequency (variable ____ and units ____)Wavelength (variable ____ and units ____)Wavelength (variable ____ and units ____)

Note: Temperature is Note: Temperature is notnot in the equations. in the equations.

v fv

f

v

f

Sound ProblemsSound ProblemsThe frequency of beats between two The frequency of beats between two

closely matched sounds can be found with closely matched sounds can be found with the following equation:the following equation:

If the sounds differ in frequency too much, If the sounds differ in frequency too much, the beats will be inaudible.the beats will be inaudible.

If the sounds are identical in frequency, If the sounds are identical in frequency, there will be ____ beat frequency.there will be ____ beat frequency.

2 1beatsf f f

Bonus SectionBonus SectionMay consist of factual information May consist of factual information

mentioned in class that is beyond what mentioned in class that is beyond what you are required to know.you are required to know.

May consist of insights from the lab that May consist of insights from the lab that you conducted on the speed of sound.you conducted on the speed of sound.