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