Waves Flashcards
The number of ocean waves that pass by a bouy in one second is called the ________________ of the wave.
Frequency
Reflection
When a wave “bounces” off of a boundary between two mediums.
Frequency
How often a wave passes a certain point in one second.
It can be measured in:
cycles/second,
waves/second,
or hertz
The _____________ of a transverse wave is its highest point.
Crest
Transmission
When a waves passes through the boundary between two mediums.
Bow Wave
A V-shaped wave created by a boat whenever the boat is moving faster than the waves move across the water.
Propagation
The repetative process a wave uses to move itself though the medium.
When you squeeze the coils of a spring together, you create a _______________.
Compression
Doppler Effect
In a while, a little button will appear above..
The change in frequency of a wave that results from motion of either the source of the wave or the observer.
In a sound wave, there are high pressure parts called a compressions. What is the name of the low pressure parts in between the compressions?
Rarefactions
Transverse wave
A wave where the medium is dispaced in a direction perpendicular to the direction the wave moves.
Destructive interference
When two waves interfer with each other in such a way that the crests of one wave line up with the troughs of the other.. The wave amplitudes cancel each other out.
__________________ occurs when two waves move into the same space in a medium and combine with each other.
Interference.
Pluck a string on a violin. The same string in violin sitting on a table nearby might vibrate in ________________.
Sympathy
(This is called a sympathetic vibration)
The ____________ is the material through which a mechanical wave travels.
Medium
Diffraction
The bending of a wave around an obstacle. This is how you can hear someone who is talking around a corner from you.
When two waves are interfering with each other, sometimes you can see nodes and anti-nodes. It almost looks like the wave is simply staying in one place. This is called a ____________wave.
Standing Wave
When a wave reflects from a surface, we call the wave that bounces off the surface the ____________________ wave.
Reflected
Adding energy at the natural frequency of an object results in _______________.
Resonance
Constructive interference
When two waves interfer with each other in such a way that the crests all line up. The wave amplitudes add.
When a wave reflects off of a surface, we call the incoming wave the __________________ wave.
Incident
In a compressional wave in a coiled spring, a __________ is where the coils are spread out.
Rarefaction
Rest position
(look at the restful water)
The position of the medium when it is allowed to come to a stop.
(Look carefully at the diagram below for the words “rest position.”)
Restoring force
A force that tends to return a medium to its rest position.
Disturbance in a medium
When the medium is displaced from its rest position.
Water waves bending around a dock is an example of _____________.
Diffraction
Node
In a standing wave, this is one of the parts that does not seem to move.
This sound has a ____________ frequency.
(Click the play button)
Low
Trough
The low part in a transverse wave.
Interference
When two waves occupying the same space combine to form a new wave.
This sound has a __________ frequency.
(Click the little button above)
The sound has a very high frequency
The type of wave made by squeezing the coils of a spring together and then letting them go is a _______________ wave.
Compressional
Medium
The substance a wave moves through
A ___________ is a repeating disturbance that transfers energy through matter or space.
wave
The __________________ of a wave is directly related to the energy of the wave. (Starts with “A”)
Amplitude
Resonance
A phenomena where the amplitude of an objects oscillations increase because it is being forced to vibrate at its own natural frequency.
The distance the particles in the medium are displaced from the rest position.
Amplitude
Wave Speed
How fast the wave travels from one place to another.
When you draw a diagram of a reflection you often draw in a line that is perpendicular to the surface. We call this line a ______________.
Normal
Crest
The high point in a transverse wave
The medium vibrates perpendicular to the direction the wave travels in these types of waves.
Transverse waves
When a wave strikes a boundary and bounces off.
Reflection
Waves bending because of a change in speed upon transferring into a new medium is called ______________.
Refraction
To find the ___________________ of a wave, you could measure the distance from one trough to the next trough.
Wavelength.
A disturbance that travels through matter or space. This disturbance transfers energy from one place to another. It is called a __________________
Wave
Beats
(press the little button above to hear some beats)
an interference pattern formed between two sounds of slightly different frequencies.
Compression
The part of a longitudinal wave where the particles are closer together. In a sound wave, it is the high pressure part of the wave.
Refraction
When a wave changes direction as it
passes from one medium to the next.
Medium
The substance through which the wave travels.
Wavelength
The distance from one crest in a wave to the next crest.
(You could also measure it from trough to trough)
In a transverse wave, the ___________ is the lowest point.
Trough
refraction
The change of direction of a wave when it moves from one medium into another.
The __________________ of a sound wave is also a measure of its loudness.
Amplitude
Seismic Wave
An earthquake wave.
The “p wave” (primary wave) gets there first
The bigger the amplitude of a wave, the more _____________ it has.
Energy
Wave motion transfers ____________ through a medium.
Energy
Are sound waves compressional/longitudinal waves or are the transverse waves.
Sound is a compressional wave.
(compressional means the same thing as longitudinal)
If you multiply the frequency of a wave by the wavelength of the wave, you will get the _____________.
Velocity of the wave
(Here is the magic triangle for this equation)
The formula for the velocity of a wave is:
We use the unit “decibels” to measure what?
Decibels measure the amplitude or “loudness” of a sound.
What type of wave requires no “medium” in order to travel?
Electromagnetic Waves
(light waves, radio waves, etc)
A change in frequency due to the motion of the source of a sound.
The Doppler Effect.
What do waves transfer from one place to another?
Energy
When you yell down the hallway to a friend, how many air particles move from you all the way to your friend.
ZERO
Waves transfer energy.
Waves do not transfer mass.
One type of earthquake wave travels along the surface of the ground and makes the buildings go up and down as the wave passes. What type of wave is this?
Compressional?
Longitudinal?
Transverse?
Torsional?
TRANSVERSE
If the wave travels horizontally along the ground, the buildings move vertically (up and down).
Thus, it is a transverse wave.
Sound is a compressional wave.
If you yell to a friend down the hall, the air particles in between will vibrate in which direction?
Horizontally.
(Its a compressional wave, so the particles vibrate in a direction parallel to the direction the wave moves.)
In this picture, the “1” is the…..
Amplitude
In this picture, the “2” is …..
A trick!
It is NOT amplitude. “1” shows the amplitude. The “2” would by twice the amplitude.
In this picture, the “4” shows the…..
Wavelength
What aspect of the wave below is remaining constant?
Wavelength is remaining constant
(The amplitude is decreasing.)
What aspect of the wave below is changing?
The amplitude is decreasing.
A standing wave can be created by two waves moving in _______________ directions.
Opposite
How many nodes in the standing wave pictured below?
TWO NODES
(one at each end)
(A node is a point in a standing wave that does not move)
How many nodes in the standing wave pictured below?
THREE NODES
(one at each end and one in the middle)
This sound has a ____________ pitch.
Low Pitch
(For sound, pitch and frequency describe the same thing)
When two waves cancel each other out, we say they are experiencing ______________ ______________.
Destructive Interference.
This sound has a __________ pitch.
(Click the little button above)
The sound has a very high pitch.
(For sound, pitch and frequency describe the same characteristic of the wave.)
The hotter it is, the ______________ a sound wave will travel.
Faster
(Sound travels fast in the desert)
When there is snow, sound travels __________.
SLOW
How could you be the first to hear a train coming?
Put your ear to the track.
(Sound travels very fast in solids.)
(Please don’t really do this)
What is one reason Dolphins can hear so well?
Sound travels
faster and better in water
than it does in air.
Speed of sound in air = 340 m/s
Speed of sound in water = 1400 m/s
Speed of sound in steel = 5000 m/s
Which color of light moves fastest in a vacuum?
All light moves the same speed in a vacuum.
(3.0 x 108 m/s)
Which moves faster in a vacuum, blue light or radio waves.
All electromagnetic waves move the same speed in a vacuum.
(3.0 x 108 m/s)
Does light speed up or slow down when it enters glass?
It slows down.
(This is why it changes direction or “refracts” a little bit when it enters the medium of glass.)
Which frequency of light travels the fastest in the vacuum of space?
ALL light travels the same velocity in the vacuum of space.
(3.0 x 108 m/s)
Which wavelength of electromagnetic radiation travels the fastest in the vacuum of space?
All electromagnetic radiation travels the same velocity in space.
(3.0 x 108 m/s)
Which color of light has the longest wavelength?
RED
Which color of light has the highest frequency?
Voilet
(Look at the wavelength of the violet light in the picture. A small wavelength means a high frequency.)
What common material can stop X-rays?
Lead
(Even a relatively thin sheet of lead can stop an X-ray)
(These are lead aprons)
The distance from A to C would be the __________ of this longitudinal wave.
one wavelength
The distance from B to D in the diagram would be the ________________ of this compressional wave.
One wavelength.
How many wavelengths are shown here.
One and a half.
How many wavelengths are shown in the entire image?
Two and a half wavelengths are shown in the image.
(A single wavelenght is labeled)
The formula relating the frequency of a wave and the period of the wave is:
The distance from B to D on th diagram would be the ______________ of this compressional wave.
One wavelength.
When the crests of two waves match up, the resulting amplitude gets larger. We say the waves are experiencing ______________ _________________.
Constructive Interference
Sound is what kind of wave?
Compressional
(aka longitudinal)
Electromagnetic waves are what kind of wave?
Transverse
(This includes radio waves, ultraviolet, infrared, visible light, x-rays, gamma rays, etc)
Which ALWAYS travels faster, sound waves or light waves?
Light ALWAYS travels faster. Much, much faster.
The time for one complete to-and-fro vibration of an object is called the ….
Period
What is the unit we use to measure the period?
Seconds
(It could be minutes or hours as well, but it must be a unit of time.)
What wave characteristic is measured in units of 1/sec?
Frequency.
(Frequency is how many times something happens PER SECOND.
(It could also be per minute or per hour, etc)
What wave phenomena happens as a result of the wave changing speed as it enters a new medium?
Refraction
(Refraction is the bending of waves due to a change in speed between two mediums.)
