Module 3: Waves and the Electromagnetic Spectrum Flashcards
Define Amplitude
the maximum displacement on either side of the euqilibriium (midpoint) position
Define Frequency
the number of vibrations per unit time; for a wave the number of crests that pass a particular point per unit time
Define Period
time required for a vibration or a wave to make a complete cycle; equal to 1/frequency
Define Wavelength
the distance between successive crests, throughs, or identical parts of a wave
Define Longitudinal Waves
a wave in which the medium bibrates ina direction parallel (longitudinal) to the direction in which the wave travels; light consists of transverse waves
Define Transverse Waves
a wave in which the medium vibrates in a direction perpendicular (transverse) to the direction in which the wave travels; light consists of tranverse waves
Define Reflection
the returning of a wave to the medium from which it came when it hits a barrier
Define Refraction
the path of a wave bends due to moving from one medium to another
Define Diffraction
spreading of wave when passing through a hole
Define Interference
the interaction of two or more waves with each other
Defne Doppler Effect
the change in frequency of a wave due to the motion of the source (or due to the motion of the receiver)
Define Sound
created when air molecules are vibrated back and forth by a vibration
Define Pitch
the quality of sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tune
- low frequency = low pitch
- high frequency = high pitch
Define Volume
corresponds to the amplitude of the sound wave
- larger amplitude = louder sound
- smaller amplitude = softer sound
Describe what a wave is
an oscillation accompanied by a trasfer of energy that travels through a medium (space or mass); wave motion transfers energy from one point to another, which displaces particles of the transmission medium
Explain the difference between a Transverse Wave and a Longitudinal Wave. Give examples of each.
- Transverse Wave
- motion occurs perpendicular to the direction of travel of the wave; think of a boat riding ocean waves
- examples: light waves, an oscillation string, seismic s-waves
- Longitudinal Wave
- motion occurs parallel to the direction of travel of the wave; think of a slinky laying on the ground and you push one end towards the other
- examples: sound waves, pressure waves, seismic p-waves (generated by explosions and earthquakes)
- FYI - Think of a long line of people holding hands. When one person jumps in the air still holding hands, this causes a chain reaction in making the next person jump up an so on and so on. This is a transverse wave. Now that same line, if the person bumps the person next to them, this will cause a chain reaction with people with bumping and bouncing off of one another. This is longitudinal wave.
Describe the below term associated with waves:
- Wavelength
the distance between successive crests, troughs or identical parts of a wave
Describe the below term associated with waves:
- Frequency
the number of vibrations per unit time; for a wave, the number of crests that pass a particular point per unit time
Describe the below term associated with waves:
- Amplitude
the maximum displacement on either side of the equilibrium (midpoint) position
Define Reflection and give an example.
Definition: occurs when a wave encounters a barrier; involves bouncing waves off an opaque surface
Examples: light bouncing off a mirror, voices bouncing off of a rock wall (also called echoes)
Define Refraction and give an example.
Definition: a wave moving from one medium to another, the wave bends at this point
Example:looking at a straw in a clear glass of water, earthquakes
Define Interference. Explain how constructive and destructive interfernce differ.
Definiton: occurs when waves interact with each other
- Constructive
- amplidtude gets bigger
- increase in sound
- light would get brighter
- Destructive
- will cancel each other out
- instead of light you would get dark
- reduces noise
- example is noise cancelling headphones
Define the Doppler Effect and describe what happens to a wave due to it.
Definition: the change in frequency of a wave due to the motion of the source (or due to the motion of the receiver)
Example: the sound a car makes when it drives past you really fast
- Sound Wavelength (Longitudinal Wave)
* the wave length will have a higher frequency as it travels twoard the objet (or a higher pitch), when it travels past the object the wavelength will lengthen and you will have a lower frequency (or a lower pitch) - Light Wavelength (Transverse Wave)
* the Doppler Radar station uses radar (a form of light) to track storms; they bounce the radio waves off the storm clouds if they send the radio waves towards the on-coming* storm, the wavelengths will be shorter, higher frequencies; if they send the radio waves towards *outgoing storm, the wavelengths will get longer, lower frequencies
A train travels toward you, emitting a horn at a frequency of 256 Hz. Due to the Doppler Effect, the frequency of sound that you hear is acutally:
- higher than 256 Hz
- lower than 256 Hz
- equal to 256 Hz
- higher than 256 Hz
Explain what property of a sound wave changes when the pitch of the sound changes.
the frequency of the vibration of a sound wave will give you the pitch of sound; when the pitch of a sound changes, the frequency changes
- higher frequency = higher pitch
- lower frequency = lower pitch
Describe the properties of light and sound for the statement/question below:
- What happens when the wavelength changes?
- Light:
- increased wavelength = softer light
- decreased wavelength = brighter light
- Sound:
- increased wavelength = softer sound and lower pitch
- decreased wavelength = louder sound and higher pitch
Describe the properties of light and sound for the statement/question below:
- What happens when the frequency changes?
- Light:
- higher frequency = softer light
- lower frequency = brighter light
- Sound:
- higher frequency = louder and high pitch sound
- lower frequency = softer sound and lower pitch
Describe the properties of light and sound for the statement/question below:
- What ahppens when the amplitude changes?
- LIght:
- higher amplitude = brighter light
- lower amplitude = softer light
- Sound: (like the volume on a radio)
- higher amplitude = louder sound
- lower amplitude = softer sound
Describe the properties of light and sound for the statement/question below:
- Is it transverse or longitudinal?
-
LIght:
* transverse wave -
Sound:
* longitudinal wave
Describe the properties of light and sound for the statement/question below:
- Media they can travel through
-
LIght:
* requires no medium, can even move through a vacuum -
Sound:
* solids (ex: Steel Wall), liquids or gases, water but not very well, air
Describe the properties of light and sound for the statement/question below:
- Example of Reflection
-
Light:
* light bouncing off a mirror -
Sound:
* voices bouncing off a stone wall (echoes)
Describe the properties of light and sound for the statement/question below:
- Example of Doppler Effect
-
LIght:
* Doppler Radar being used to track storms -
Sound:
* car driving by you with the horn going
Describe the properties of light and sound for the statement/question below:
- Example of Interference
- Light:
- Constructive - light would get brighter
- Destructive - no light only dark or dimmer
- Sound:
- Constructive - increase in sound
- Destructive - reduces noise (noise cancelling headphones)
Describe the properties of light and sound for the statement/question below:
- Example of Refraction
- Light:
- putting a straw in a clear glass
- light hitting a prism
-
Sound:
* being able to hear someone across a lake early in the moring, the air is cooler closer to the water, bending the sounds so they travel faster
Sound travels fastest in:
- air
- water
- steel
- a vacuum (nothing at all)
- steel
True or False
Light requires a medium to move through.
False
Which of the following is NOT a transverse Wave?
- sound
- light
- water
- “the wave” at the stadium
- sound
Define Electromagnetic Spectrum
the range of the electromagnetic waves that extends in frequency from radio waves to gamma waves
Define Electromagnetic Wave
an energy-carrying wave produced when an electric charge oscillates
Describe what an Electromagnetic Wave is
an energy-carrying wave produced when an electric charge oscillates; aka LIght; they are all transverse waves; requires no medium to propagate through meaning it can move through the vacuum of space with no problems; light is always moving fast
List the types of electromagnetic waves that are located on the electromagnetic spectrum.
- Radio Waves (long wavelength, low energy, low frequency)
- Microwaves
- Infrared
- Visible Light (light we see, middle of spectrum)
- Ultraviolet Light
- X-rays
- Gamma Rays (short wavelength, high energy, high frequency)
Name the electromagnetic wave that correspond to the trick statements:
- _G_ood _X_ylophones _U_se _V_ery _I_nteresting _M_usical _R_hythm
- Real _M_en _I_n _V_egas _U_se _X_-ray _G_oggles
- Gamma Rays
X-Rays
Ultraviolet Lights
Visible Light
Infrared
Microwaves
Radio Waves
- Radio Waves
Microwaves
Infrared
Visible Light
Ultraviolet Light
X-Rays
Gamma Rays
Explain how electromagnetic waves are similar and different.
- Similar: they can all transfer energy
- Different: depending where they fall on the spectrum depends on how much energy they can transfer
Describe common proactical applications for each of the different types of electromagnetic waves.
- Radio Waves - cell phones, RFID (tags you find in clothes)
- Microwaves - microwave oven, microwave telecommunication dish
- Infrared - searching for heating leaks in a power plant or house
- Ultraviolet - sterilization of food/equipment
- X-rays - imaging for medical/security applications
- Gamma Rays - cancer treatments
Which of the following is most unlike the others?
- Radio Waves
- Gamma Rays
- Visible Light
- Sound Waves
- Microwaves
- Sound Waves
- Radio Waves (light)
- Gamma Rays (light)
- Visible Light (light)
- Sound Waves (sound)
- Microwaves (light)
Sound travles fastest in:
- air
- water
- steel
- a vacuum (nothing at all)
- steel
Which type of electromagnetic radiation possesses the most energy?
- Radio Waves
- Gamma Rays
- Visible Light
- Micorwaves
- X-rays
- Gamma Rays
Which type of electromagnetic radiation possesses the longest wavelength?
- Radio Waves
- Gamma Rays
- Visible Light
- Micorwaves
- X-rays
- Radio Waves
Which type of electromagnetic radiation is utilized in night-vision glasses?
- Infrared Light
- Gamma Rays
- Visible Light
- Mocrowaves
- X-rays
- Infrared Light
Which type of electromagnetic radiation is utilized in transmitting cell phone calls?
- Infrared Light
- Gamma Rays
- Visible Light
- Radio Waves
- X-rays
- Radio Waves
Which type of electromagnetic radiation is utilized in radiation therapy for cancer?
- Infrared Light
- Gamma Rays
- Visible Light
- Radio Waves
- X-rays
- Gamma Rays
