Physics chapter 27 and 28

what is the wavelength of a radio wave with frequency 100.3 MHz?

2.99m

What was Albert Michelson's experimental value for the speed of light?

300,000km/s

how can you see photographs or movies in 3D?

A pair of photographs or movie frames, taken a short distance apart (about average eye spacing), can be seen in 3-D when the left eye sees only the left view and the right eye sees only the right view.

How did Isaac Newton show that sunlight is composed of a mixture of all colors of the rainbow?

By passing a narrow beam of sunlight through a triangular-shaped glass prism.

who figured out that when the Earth was farther away from jupiter, it was the light that was late, not the moon?

Christian Huyges

The color of an object we see is determined by __________

Colors of light reflected by the object, frequencies of light absorbed, colors of light shining on the object, frequencies of light reflected by the object

ultraviolet

Electromagnetic waves of frequencies higher than those of violet

infrared

Electromagnetic waves of frequencies lower than the red of visible light

electromagnetic spectrum

Light is a small portion of the broad family of electromagnetic waves that includes such familiar forms as radio waves, microwaves, infrared, light, ultraviolet rays, X-rays, and gamma rays.

electromagnetic wave

Light is energy that is emitted by accelerating electric charges—often electrons in atoms. This energy travels in a wave that is partly electric and partly magnetic.

Why is glare from a horizontal surface horizontally polarized?

Light that reflects at glancing angles from nonmetallic surfaces, such as glass, water, or roads, vibrates mainly in the plane of the reflecting surface.

who made the first demonstration that light travels at a finite speed?

Olaus Roemer

What determines the color of a transparent object?

The color of a transparent object is the color of the light it transmits.

What determines the color of an opaque object?

The color of an opaque object is the color of the light it reflects.

the complementary color of yellow is _____

blue

which visible frequencies make up the brightest part of sunlight?

Yellow-green light

subtractive primary colors

magenta, yellow, and cyan

White light

a combination of all the colors. white is not a color but a combination of all colors.

When a sample of an element is heated until it glows, the color it gives off is _______

a composite of many frequencies of light

prenumbra

a partial shadow

line spectrum

a pattern of distinct lines of color, with each line corresponding to a frequency of light

scattering

a process in which sound or light is absorbed and reemitted in all directions

Spectrum

a spread of colors: red, orange, yellow,green, blue, and violet.

exited state

a state with greater energy than the atoms lowest energy state.

ray

a thin beam of light

umbra

a total shadow

Color seen on a TV screen result from color ______

addition

what happens to an excited atom after it emits light?

after an exited atom emits light, it returns to its normal state

why are sunsets red?

by the time a beam of light gets to the ground at sunset, all of the high frequency light has already been scattered. only the lower frequencies remain, resulting in a red sunset.

a sheet of red paper will look black when illuminated with _____

cyan light

solar eclipses are seen less often than lunar eclipses because _________

earth's shadow on the moon is larger than the moon's shadow on the earth

what happens when you combine any color with its complementary color?

every color has some complementary color that when added together to it will produce white

T or F? a thin beam of light is called an X-ray

false

T or F? electromagnetic heat waves are called ultraviolet waves

false

T or F? glass transmits ultraviolet and visible light but not infrared waves

false

T or F? infrared waves are responsible for sunburn

false

T or F? materials that allow light to pass through them in straight lines are called opaque materials

false

photons

massless bundles of concentrated electromagnetic energy

T or F? vision in 3D depends on the fact that both eyes give impressions simultaneously, each eye viewing a scene from the same angle

false

different colors of light correspond to different light ________

frequencies

if an electron vibrates up and down 1000 times each second, it generates an electromagnetic wave having a _______

frequency of 1000Hz

If sunlight were green instead of white, the most comfortable color to wear on a hot day would be _____

green

the complementary color of magenta is ______

green

What colors overlap to make cyan?

green and blue

the true color of water is ______

greenish-blue

The colors of light emitted by incandescent, glowing gases show the _____

identities of atoms in the gas

why does light not pass through opaque materials?

in opaque materials, any coordinated vibrations given by light to the atoms and molecules are turned into random kinetic energy--that is, into internal energy

heat lamps give off mostly _______

infrared waves

why is the sky blue?

its component particles scatter high frequency light

what kind of materials does light pass through?

light passes through materials whose atoms absorb the energy and immediately reemit it as light

compared to the wavelength of ultraviolet waves, the wavelength of infrared waves is _______

longer

the three colors that are utilized for color subtraction are ________

magenta, cyan, and yellow

opaque

materials that absorb light without reemission and thus allow no light through them, ex: wood, stone, and people

the complementary color of cyan is _____

red

what colors overlap to make magenta?

red and blue

what colors overlap to make yellow?

red and green

the colored dots that make up a TV screen are ____

red, blue, green

what colors overlap to make white?

red, green, and blue

Earth receives much ultraviolet radiation from the sun. Luckily, most of it doesn't reach the ground because it is ______

scattered by the upper atmosphere

what is the nature of light?

scientists now agree that light has a dual nature, part particle and part wave (particle theory)

a ________ is formed where light cannot reach

shadow

electromagnetic waves with higher frequencies have wavelengths that are _____

shorter

compared to its speed in air, the speed of light in water is _________

slower

light-year

the distance light travels in one year

what are the waves of the electromagnetic spectrum?

the electromagnetic spectrum consists of radio waves, microwaves, infrared, light, ultraviolet rays, x-rays, and gamma rays.

polarization

the fact that light waves are transverse and not longitudinal is demonstrated by this phenomenon

the shiny surfaces of metals have most to do with _________

the free electrons in metal atoms

radiation curve

the graphical distribution of brightness versus frequency

Light shines on a pane of green glass and a pane of clear glass. the temperature will be higher in ________

the green glass

spectroscope

the light from glowing elements can be analyzed with this

pigment

the material in the glass that selectively absorbs colored light

additive primary colors

the primary color elements that make up white light; red, green, and blue

compared to the velocity of radio waves, the velocity of visible light waves is _____

the same

the primary purpose of polarized glasses is _______

to block glare from reflections

materials that transmit light are _____

transparent

electromagnetic waves are _______

transverse waves

electromagnetic waves can _______

travel through a vacuum

T or F? According to Einstein, light consists of mass-less bundles of energy called photons

true

T or F? Energy emitted by vibrating electric charges is carried by electromagnetic waves

true

T or F? If an object were completely black, you wouldn't be able to see it directly

true

T or F? Material in an object that selectively absorbs colored light is called a pigment

true

T or F? Tennis balls are yellow-green because our eyes are most sensitiv eto that color

true

T or F? a total shadow is called an umbra

true

T or F? light sometimes acts as a wave and sometimes as a particle

true

polarization occurs when waves vibrate in a single direction

true

a certain beam of blue light shines with a wavelength of 480 nm next to and parallel to a beam of ultraviolet light with a wavelength of 240 nm. the frequency of the ultraviolet is ______

twice that of the blue light

the source of all electromagnetic waves is __________

vibrating charges

why is water greenish-blue?

water molecules absorb red

velocity equation

wavelength X frequency

which visible frequencies are absorbed by a mixture of paints or dyes?

when dyes or paints are mixed the mixture absorbs all the frequencies each paint or dye in it absorbs

what causes the formation of shadows?

when light shines on an object, some of the rays may be stopped while others pass on in a straight-line path

complementary colors

when two colors are added together to produce white

Sunlight contains all colors of light, but it is most intense in the ________

yellow

which three visible frequencies combine to form almost any color?

you can make almost any color by overlapping red, green, and blue light and adjusting the brightness of each color of light.

if two polarizing 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 _____

zero