Light Flashcards
What type of wave is light
Light is a transverse wave. This means that the medium moves perpendicular to the wave.
Light doesn’t need a medium to travel. It consists of alternating electric and magnetic fields
What evidence is there that light is made up of particles
What are photons
List the Electromagnetic Spectrum from Longest to Shortest
What are uses for radio waves
Radio Waves: AM and FM radio, television, broadcasting, radar, aircraft navigation
Infrared Waves (Uses)
Microwaves: Atomic and molecular research, microwaves, microwave ovens
What are uses for Visible Light
What are uses for ultraviolet light
Ultraviolet Light: Sterilizing medical instruments, identifying fluorescent minerals
What are uses for X Rays
X-Ray: Medical examinations of bones, teeth, organs, and cancer treatments
What are uses for gamma rays
Gamma Ray: Food Irradiation, studies of structural flaws in thick materials
As you change wavelength what happens
In visible light, if you change the amplitude,
Define the following words
Absorbed
The light is taken in by some mass
Reflected:
Use the law of reflection, and you see that the light bounces off in another
direction
Scattered:
Refracted::
Transmission:
Is the ability of light to pass through something. It will usually go through
something with a low index of refraction.
Why is the Sky Blue?
More energetic waves scatter better. This is more towards the ultraviolet part. When light
shines down onto the earth, the parts of the visible spectrum scatter. Molecules in the atmosphere
absorb and scatter light. Less energetic light tends to not scatter as much. In addition, it will get
absorbed.
EXAMPLES OF DEFINITIONS
- A rock will absorb all colors of light.
- Glass reflects light
- Light reflecting on tin foil will scatter it
- The eye refracts light
- Thin Cotton will transmit light
In order, absorbed, reflected, scattered, refracted, transmited
Opaque
Transparent:
having the property of transmitting raysof light through its substance so
that bodies situated beyond or behind can be distinctlyseen.
Translucent:
To see an object as a particular color,
To see an object as a particular color, light, that color must be reflected back to your eyes,
while the other colors are absorbed. For example, in a leaf, visible light shines down on it,
however, all of the other colors are absorbed while only green reflects back.
What are the additave and subtractive properties
When you mix primary colors ( red, green, blue), you can create new colors. This is the same
with light. When you mix primary colors, you can create secondary colors such as Yellow, Cyan,
and Magenta. These are called the additive primary colors. Subtractive primary colors are
essentially the secondary colors that can be combined to create green, red, and blue. If all of
the pigments of the there colors are combined, (secondary) then the light is absorbed and you
get black
What are primary colors
What color light refracts the most ( relate rainbows and prisims)
Violet light refracts the greatest amount of light. This is because of Violet Light’s
wavelength. When white light passes through a prism, all of the colors bend, and then the
light seperates. This is called dispersion. In a rainbow, the light hits the water droplets in the
sky and disperses. Because all of the parts of light disperse at different angles, you are able
to see them.
What is evidence that infrared light is also light
Dopplar Effect
The Doppler Effect can be observed with light. This happens when there is a moving object
that is going. When something is moving, the light is traveling at a constant, the rate that it is
traveling at also depends on the velocity. If a bug is making a noise and coming close to you,
the time that it makes the noise is constant. But it is approaching you, so the waves don’t
have to travel as far to reach you, thus you will get a shorter wavelength which means a
higher frequency. But on the other side, the bug is moving away from you, so that means it
has to travel further, giving it a longer wavelength and thus a lower frequency.
PolarizedLight
Light is always magnetic in the y axis and electric in the x axis. But, the electric field is going
all around in different directions. The electric field travels in the x and y coordinate plane.
So, what a polarizer does is limit the electric field to one specific part, and the light that
passes through that is what you see. Polarized sun glasses means that it only allows light from
a specific direction.
