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157 Cards in this Set

  • Front
  • Back
electromagnetic waves are what types of waves?
transverse
electromagnetic waves can/can't travel through a vacuum.
can
WHich visble light wave had the shortest wavelength?
violet (ROY G BIV goes longest to shortest)
compared to the wavelength of a ultraviolet waves, the wavelength of infrared waves is____________.
longer
Compared to the velocity of radio waves, the wavelength of infrared waves is _____________________ and ________________.
-same in a vacuum
-slower in a medium
the source of all electromagnetic waves is___________.
vibrating electric particles
The main difference between a radio wave and a sound wave is its_______________.
basic nature of the waves
radio waves travel at the speed of light, 300,000. The wavelength of a radiowave recieved at 100MHz is _______.
3 meters
sound waves in the air are a series of _____ or __________.
compressions or longitidunial waves
the speed of a sound wave depends on what?
temperature
When the handle of a tuning fork is held solidly against a table, the sound becomes louder and the length of the fork vibrates ______________
become shorter
the phenomenon of beats results from _________________.
wave interface
What is the time needed for a wave to make one complete cycle?
period
A 340Hz sound wave travels @ 340m/s in the air, with a wavelength of ________.
1 meter
Beats are produced when two tuning forks, one of 240Hz and the other of frequency 246Hz are sounded together. The frequency of beats is what?
6Hz
The distance between the sucessive identical parts of a wave is called its what?
wavelength
What is hertz a unit of?
frequency
What type of wave is created when shaking a rope up and down?
transverse wave
What is it called when two or more waves are at the same place at the same time?
interference
Where can you touch a standing wave on a rope without disturbing the wave?
node
What is the doppler effect?
the change in observed frequency due to the movement by the observer or the source of sound
When a sound source moves towards you, what happens to the wave?
it stays the same
Some of a wave's energy is always being dissipated as heat. In time this will reduce the wave's _______________.
amplitude
If the amplitude of a particular wave is 1 meter, what is the top-to-bottom distance of the disturbace?
2 meter
If you double the frequency of a vibrating object, what will its period do?
decrease
You dip your finger repeatedly into water and make waves. If you dip your finger into more frequently, the wavelength of the wave does what?
decreases
A child swings on back and forth on a swing. If the child stands rather than sits, the time for the swing to go back and forth_______________.
decreases
What happens when an airplane is flying faster than the speed of sound?
sonic boom occurs
When observer on the ground hears a sonic boom, how fast is a plane going?
faster than the speed of sound
When does the doppler effect occur?
when a source of sound moves towards an observer
What is the frequency of the second hand on a clock?
1/60 of a second
Two wavelngths arrive at the same place at the same time exactly in step with each other. Each wave has an amplitude of 1 meter. The resulting wave will have an amplitude of what?
2 meters
A certain ocean wave has a frequency of 0.05Hz and a wavelength of 10 meters. What is the wave's speed?
5m/s
THe period of an ocean wave is 10 seconds. What is the wave's frequency?
1/10Hz
A weight on the end of a spring bobs up and down one complete cycle every 2 seconds. Its period is ______.
1/2Hz
A weight on the end of the a spring bobs up and down one complete cycle every 2 seconds. WHat is its period?
1/2 second
How long does it take the sun to reach the earth?
8 minutes
A leaf on a pond oscillates up and down two complete cycles each second as a water wave passes. What is the speed's frequency?
2Hz
What do heat lamps usually give off?
infrared
When in the water the speed of light is faster/slower than when in the air
slower
Glass is transparent to visible light but not to ________________________.
loose electrons
What has to do with shiny surfaces of metals?
loose electrons
Do clouds block UV light?
no
What color travels fastest through clear glass?
red
If a shadow is produced by an object held close to a peice of paper in the sunlight, how will the image on the peice of paper show up?
sharp
What is the ultimate source of electromagnetic waves?
vibrating charges
If a photographer wishes to use a safety light in the dark room that will emit low-energy photons, what is the best color of light for him to use?
red-the lowest energy
What color light carries the most energy?
violet
How fast is a light second?
300,000km
After randomly polarized light passes through a polarizer, it is __________
polarized?
If two polarized filters are held with their polarization axes at right angles to each other, the amount of light transmitted compared to when their axes are parallel is________.
0
Sunlight contains all colors but it mainly contains what color?
yellow
The earth recieves a lot of ultraviolet radiation from the sun. Luckily most of it doesn't reach the ground beacause it is__________________________.
blocked by the ozone layer
Light shines on a pane of green glass and a pane of clear glass. The temperature will be higher in what pane of glass?
green glass
Color is seen on tv thanks to what?
color addition
A tennis ball is more easily seen if it is what color?
yellow-green
Different colors of light correpond to different_________________.
light frequencies
What are complimentary colors?
two colors that produce white light
When yellow and blue are mixed together to create green, what colors are absorbed?
all except green
The simularity/difference between Columb's law and Newton's law of gravity
similarity- both vary inversely to the square of the proportion

difference- gravity only attracts while the other attracts and repels
What is the difference between an insulator and a conductor? Which is copper? Wood? Distilled water?
an insulator doesn't allow the flow of electricity while a conductor does and creates electricty
What are three ways an object can become charged? explain each.
friction-rubbing 2 objects together

contact- a charged object coming in contact w/an insulator that has tightly bound electrons

induction- a charged object coming close but not touching another charged object
WHy should you not sit or stand in water when using electrical appliances?
b/c water is a good conductor
Columbs law says there are two kinds of charges. What are they?
positive and negative
A material is a good insulator if?
it has tightly bound electrons
A material is a good conductor if?
it has tightly bound electrons
Semiconductors are good conductors and insulators. Explain.
they are good conductors until they are induced to change state
Atomic nuclei almost always consists of what?
protons and neutrons
What do two like charges do?
repel
What do protons and electrons do?
attract
Electrical forces between charges are normally strongest when the charges are close/far apart?
close
Columb's law says that the force between any two objects depends on what?
amount of charge and the distance between the charges
WHen the distance between two charges is halved the electrical force between the charges is what?
quadroupled
A positive ion has what?
more protons than electrons
If you comb your hair and the comb becomes positively charged, your hair becomes _______________.
negatively charged
Charge carriers in a metal are electrons rather than protons because electrons are ______________.
negative
Bring a charged object near a conductor and then momentarily touch the conductor. This demonstrates charge by______________.
contact
Two charged particles held close to each other are released. As they move, the acceleration decreases. Therefore, the particles have what kind of charges?
like charges
What is an electric field?
a force field that fills the space around every charge or group of charges
What are field lines and how are they represented?
force per charge.... vectors
A mass of protons has what two types of fields around them?
gravity and electric
A positive test charge in a field determines what properties of the field?
magnitude and direction
A large positive charge is transferred to a large metal sphere, what is the field strength:

a. outside the sphere

b. inside the sphere
a. very large

b. zero
What is the field strength inside a sphere and why is it that value?
zero b/c the charges are evenly distributed
What is electric potential energy determined by?
the charge's location
identify whether the potiental energy increases or decreases for the following:

a. a positive charge moved closer to a negative charge

b. a positive charge moved closer to a positive charge

c. a negative charge moved closer to a negative charge

d. a negative charge moved closer to a positive charge

e. a positve charge moved away from a negative charge

f.a positive charge moved away from a positive charge

g. A negative charge moved away from a negative charge

h. a negative charge moved away from a positive charge
a. decreases
b. increases
c. increases
d. decreases
e. increases
f. increases
g. decreases
h. increases
what is a volt?
a unit of electric voltage
What is an ampere?
a unit of electric current
What is a Van de Graff generator?
a machine that generates large electric voltages
A beam of electrons accelerate from the back of your tv set to the screen. In order to make the beam hit the bottom of the screen, oppositely charged parallel plates create a vertical electric field. How will the top plate be charged?
negatively
Two parallel plates are oppositely charged. The left plate is negative and the right plate is positive. In which direction does the electric field point?
positive towards negative
Electric field lines between two oppositely charged parallel metal plates will be _______________ and _____________.
parallel and have an equal distance
The electric field inside an uncharged metal ball is zero. If the ball is negatively charged, the electric field inside the ball must be ______?
zero
What is required in order for there to be a flow of charge from one place to another?
ther must be a conductor and an electric potential difference
In solid conductors, electric current of flow is___________
electrons
an ampere is a measurement of what?
current
Electric resistance in a wire depends on a wire's ______________ (3 things)
-conductivity
-temperature
-thickness
Compared to thin wires, electric resistance in thick wires is __________.
less
For most conductors, as their temperature increases, their resistance____________.
increases
A man experiences electric shock. Where do the electrons making the shock come from?
the man himself
A wire carrying current is normally charged ____________.
not at all
Current from a battery is always what?
direct current
Where do electrons come form that produce heat and light in a filamentof the light bulb?
the filament
If you plug a hair dryer rated at 110V into a 220V outlet, the current in the hari dryer will be__________.
doubled
Electric power is ________ times ________.
voltage times current
The current through a 12 ohm resistor connected to a 220V power supply is______
10 amps
A 1000 ohm resistor has a 5 amp current in it. What is the voltage across the resistor?
30 amps
What is the resistance of a toaster that uses 4 amps when connected to a 120V power source?
30 ohms
How much power is used by 12.0V flashlight battery that draws .25A of current?
3 watts
When plugged into a 120V wall outlet, how much current used by a toaster rated at 2400W?
20 A
A 100W light bulb is connected to a 120V outlet. How much current exsists in the light bulb?
.83A
A power line with a resisatnce of 2 ohm has a current of 100A in it. The power dissipated in the line is _________
20000 watts
What does the law of reflection state?
that the angle of reflection is equal to the angle of incidence
What is known about the virtual image created in a mirror
-reflected rays diverge
-image behind mirror
-image upright
When a light beam emerges from water into air the average light speed _______.
increases
What mostly has to do with a mirage?
diffraction
Different colors trael at different speeds in a transparent medium. In a vacuum, different colors of light travel at ____________.
the same speed
The spectrum produced by a prism or a rain drop is evidence that the average speed of light in a material depends on the light's _______.
color
If you walk towards a mirror at a certain speed, the relative speed between you and your image is what?
quadroupled
What is the shortest a plane mirror can be to see your whole image?
1/2 your height
What does a beam of light travel fastest in?
a vacuum or the least dense material
In a curved optical fiber, light travels ____________
internally reflects in a sucession of straight line paths
What is the rainbow an example of?
diffraction
A converging lens ___________________.
bends parallel rays at single points
An image of a distant object formed by a single converging lens is....
-real
-upside down
-can be focused on a machine
-can be projected on a wall
What is a magnifying glass?
a converging lens
The reason the bottom lines of a swimming pool can look wavy when seen from above is beacuse _________________.
the uneven water surface is refracting at different angles
If an object is located at a focal length of the diverging lens, then compared to the object, the image will appear _________.
smaller
If an object is located inside the focal lens, the image will appear to be ___________.
right side up
All lenses rely on having a ____________.
slower speed in the lens
WHich instrument is the human eye most similar to?
camera
A simple astronomical telescope consists of a pair of ______ lenses.
converging
When slides are put right side up into a slide projector, the images are _____________.
upside down
If light traveled at the same speed in glass as it does air, images would look ______________.
the same w/o a telescope
The image your eye recieves is _______.
upside down
on a bright day, the iris of the eye changes so the pupil ________.
becomes smaller
All magnifying glasses under water will _____________.
magnify less
The wavy bright and dark lines at the bottom of the pool are a resultof the water surface acting like moving _________.
lenses
Suppose you are 2 meters in fornt of a plane mirror and you want to take your picture. From what distance should you take the picture?
4 meters
Huygens' priciple says that _______________.
each point on awave acts as a new wavelet
As you get farther and farther away from a point source of waves the wave fronts appear ___________.
flatter
When a plane wave passes through a n opening, the wave fronts will not change much if the opening is _________.
large compared to the wavelength
When a wave passes through an opening some of the wave is bent. What is this called?
diffraction
Diffraction occurs for what types of waves?
all
What is diffraction the result of?
interference
Colors seen when gasoline forms a thin film on water are a demonstration of what?
destructive interface
When do wave diffract the most?
when their wavelengths are long
Constructive interface occurs when __________.
the crests OR troug
Destructive interface occurs when_________.
crests AND troughs overlap
When monochromatic light shines through two closely spaced narrow slits and onto a screen some distance away, the pattern on the screen has ____________.
alternates of light and dark
A diffraction grating consists mostly of _________.
many closely spaced narrow slits
What is it called when gasoline drips onto a wet street and you can see a beautiful spectrum of colors?
irridescence
A thin film appears blue when illuminatedwith white light. The color being canceled by destructive interface is _______.
all colors except blue
What is coherent light?
many different rays of light all having the same phase, frequency, wavelength, and direction
What is light emitted by a laser?
coherent
A hologram is most closely related to a _________.
diffraction grating
Monochromatic light refers to light that is what?
of only one color