Chapter 12 & 13 - Waves and Sounds

the shorter the air column is the higher

the pitch

what happens to the speed of a wave if the medium, temperature, and pressure do not change?

the speed stays the same

echo location

the use of reflected sound waves to determine distance or to locate objects

echolocation

the use of reflected sound waves to determine distances or to locate objects

how is sonar similar to ultrasound imaging? how is it different?

they both locate objects using ultrasound. sonar is used underwater, while ultrasound is imaging of body tissue

how are transverse and longitudinal waves alike and diffent?

they both vibrate the medium. transverse vibrates at different angles and longitude spacing between the cals varies

how do bats use sound to navigate and to hunt?

they send out short pulses of ultrasound waves. the waves reflect off objects and return to the bats ears

what are two uses for sonar

to detect and locate objects under water

what is one way ultrasound is used in medicine?

to look inside the human body

what type of mechanical wave is this?

transverse wave

now i know that three types of mechanical waves are

transverse waves, longitudinal waves, and surface waves

the letter D represents the ____________ of the wave

trough

decibel (dB)

unit of comparison for loudness

in a wind instrument, the air colum

vibrates

now i know that for any wave, wavelength describes

wavelength

the letter B represents the ____________ of the wave

wavelength

what causes nodes to form in a standing wave?

when destructive interference produces points with zero amplitude

what causes resonance to occur?

when external vibrations match an objects natural frequency

What creates the Doppler effect?

when the motion of the sources cause the waves to either get closer together or spread out

four complete waves pass the duck in one second. the frequency of this wave is

4 Hz

loudness

Awareness of the energy of a sound

pitch

How high or low a sound seems

what are the types of mechanical waves?

Transverse, longitudinal, and surface waves

what is a diffraction

When a wave moves around a barrier or through an opening in a barrier, it bends and spreads out

making sound waves

a sound wave begins with a vibration, the vibration disturbs nearby air particles. compressions and rare fractions travel through the air as longitudinal waves

now i know that a mechanical wave forms when

a source of energy causes a medium to vibrate

sonar

a system that uses reflected sound waves to detect and locate objects under water

standing wave

a wave that appears to stay in one place

the letter A represents the ____________ of the wave

amplitude

name four properties of a wave. tell what each property describes.

amplitude - how far the medium in a wave moves wavelength - a wavelength frequency - how often it occurs speed - how quickly a wave moves

what are the properties of waves

amplitude, wavelength, frequency, and speed

now i know that the two types of wave interference are

constructive and destructive

the letter C represents the ____________ of the wave

crest

label the parts of the wave shown by the rope

crest, trough

As wavelength increases, the pitch

decreases

the intensity of a sound wave__________ with distance

decreases

the thicker the string is the pitch

decreases

how much matter or mass there is in a given amount of space or volume.

density

____________ interference is used in some headphones to block out distracting noises in a listener's surroudings

destructive

intensity

energy a sound wave carries per second through a unit area

how do you know the wave is a mechanical wave?

hand, the medium

now i know that for any wave, amplitude describes

how far the medium in a wave moves

now i know that for any wave, frequency describes

how often it occurs

now i know that for any wave, speed describes

how quickly a wave moves

resonance

increase in amplitude that occurs when external vibrations match an object's own natural frequency

As tension increases, the pitch

increases

the thinner the string is the pitch

increases

the amount of energy a sound wave carries per second through a unit area is its

intensity

constructive interference

interaction of two waves that results in a wave with a larger amplitude

destructive interference

interaction of two waves that results in a wave with a smaller amplitude

sound

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

how does sonar work?

it sends a burst of ultrasound waves that travel through the water and locate objects

compared to the direction it travels, at what angle does a transverse wave vibrate a medium?

it vibrates a medium at right angles or perpedicular

if an incoming wave and reflected wave have _____________ frequency, they combine to form a standing wave

just the right

speed of light vs sound

light is faster than sound

what property of sound depends on the energy and intensity of the sound wave?

loudness

what happens when a source of energy causes a medium to vibrate?

mechanical waves form

now i know that animals use echolocation to

navigate and find food

humans use ultrasound technologies to

observe things that they cannot see directly

the speed of sound depends

on the temperature, stiffness, and density of the medium the sound travels through

now i know that a wave's direction an be changed by

reflecting, refracting, and diffraction

a wave bends after entering a new medium. what type of interaction is this

refraction

waves change direction by diffraction, reflection, and

refraction

what medium is the wave traveling through

rope

diffraction of sound waves

sound waves can diffract or bend around the edges of an opening such as a doorway. they can also diffract around obstacles or corners

How do sound waves travel?

sound waves carry energy through a medium without moving the particles of the medium along; each particle of the medium vibrates as the disturbance passes, when the disturbance reaches your ears you hear the sound

how are three of the properties in the above question similar?

speed = wavelength x frequency

what is the formula for a wave's speed?

speed = wavelength x frequency

now i know that wavelength, frequency, and speed are related by the formula

speed = wavelength x frequency frequency = speed/wavelength wavelength = speed/frequency

the speed of sound depends on the___________ of the medium.

stiffness (solids are stiffer than liquids or gases)

In a given liquid or gas, sound travels more slowly at lower____________ than at higher _______________.

temperature

diffraction

the bending and spreading out of waves around the edge of a barrier

now i know that the loudness of a sound depends on

the energy and intensity of the sound wave

what determines the pitch and loudness of sound

the frequency

now i know the pitch of a sound that you hear depends on the

the frequency of the sound

what does the pitch of a sound depend on?

the frequency of the sound wave

what is the source of energy causing the wave?

the hand

now i know that standing waves form when

the incoming wave and reflected wave have just the right frequency, they combine to form a wave that appears to stand still

interference

the interaction between two waves that meet

now i know that the Doppler effect occurs because

the motion of the source causes the waves to either get closer together or spread out

sonogram

the picture

the longer the air column the lower

the pitch