Physics 1320 test 1 Study Questions

A piece of glass that appears red seen in transmission mode

(both of these), transmits red, absorbs or reflects all colors except red

What is the frequency of an electromagnetic wave that has a wavelength of 300,000 km?

1 Hz

Find the time interval between light leaving and returning to the revolving mirror.

1.0x10^-4 seconds

Find the time for a pulse of laser light to reach the Moon and to bounce back to Earth.

2.5 seconds

If we were to receive a radio message from this star today, find the time when it would have been sent.

4.4 years ago

If the Sun were to disappear at this moment, we wouldn't know about it for

8 minutes

Which travels faster through a vacuum - an infrared ray or a gamma ray?

Both travel at the same speed, c.

When we look at the Sun, we are seeing it as it was 8 minutes ago. So we can only see the Sun "in the past." When you look at the back of your own hand, do you see it "now" or in "the past"?

I see it in "the past"

Which of the following can not travel in a vacuum?

Sound

While Earth is experiencing a total solar eclipse, an observer on the side of the Moon facing Earth would see

a dark area moving across the face of earth.

the solar radiation curve

a plot of Sun's brightness versus frequency of emission.

Which best shields you from sunburn when at the beach?

a sheet of glass between you and the sun

The main difference between the retina of a human eye and that of a dog's eye is the

absence of cones in a dogs retina.

When the frequency of light matches the natural frequency of molecules in a material, light is

absorbed

Materials generally become warmer when light is

absorbed by them.

The greenish blue of water is evidence for the

absorption of red light

The source of all electromagnetic waves is

accelerating electric charges.

Colors seen on some TV screens result from color

addition

If three primary colors of light shine on a white wall and produce a white spot, the primaries must be

additive

Your friend says that any radio wave travels in vacuum appreciably faster than any sound wave.

agree with your friend unconditionally

Our eyes are not very good at seeing

all of the above (motion in our periphery, colors in dim light, differences in brightness)

Which travels greatest speed in a vacuum (gamma, x, light, radio)

all of these travel at the same speed

In air, radio waves

always travel much faster than sound waves.

A helium-neon laser emits light of wavelength 633 nanometers (nm). Light from an argon laser has a wavelength of 515 nm. Which laser emits the higher-frequency light?

an argon laser

Compared to the photon that enters a pane of window glass, the photon that emerges is

an identical but different proton

A total shadow is called

an umbra, and a partial is a penumbra

Glass is transparent to wave frequencies that

are below its natural frequencies.

When visible light is incident upon clear glass, atoms in the glass

are forced into vibration

Information-carrying nerves are connected to the retina at the

blind spot

A banana will appear black when illuminated with

blue light

A main difference between a radio wave and a light wave is

both (wavelength and frequency)

If a light signal and a radio signal were emitted simultaneously from Alpha Centauri, the first to reach Earth would be the

both at the same time.

If the color spectrum ranges from red to violet, then it ranges from

both of these (low frequency/long wavelength to high high frequency/short wavelength)

The fact that you can see stars in the nighttime sky is evidence that

both of these (our atmosphere is transparent to visible light, and light can travel in a vacuum)

When you see the colors on the cover of your physics book lying on your desk, what is occuring at the surface of the book?

color subtraction

The sensation of color is seen when light falls on the eye's

cones

Stare at a red wall for a few minutes and then gaze at a white wall. Due to retina fatigue you see

cyan

A red apple will appear black when illuminated with

cyan light

The crescent shapes of spots of light cast through openings in trees occurs

during partial eclipse of the Sun for the point of the observation.

An annular eclipse of the Sun occurs when the Moon doesn't quite cover the Sun in the zone of totality. This means that the Moon is

farther than usual from earth

What characteristic of light mostly relates to color?

frequency

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

frequency of 1000 HZ

A mixture of cyan and yellow pigments appears

green

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

green

Infrared waves are often called heat waves because they

induce resonance in molecules and increase internal energy in a substance.

The part of the electromagnetic spectrum most absorbed by water is

infared

Earth's atmosphere is opaque to waves that are concentrated in the

infared part of the spectrum

Most of the waves in the electromagnetic spectrum are

invisible

The sky is usually the deepest blue

is just after a rainstorm.

Colors are barely seen or not at all in nighttime because moonlight

is too dim to activate the retinas cones.

saying an apple is red means that

it appears red

Compared to its average speed in air, the average speed of a beam of light in glass is

less

If an electric charge is shaken up and down frequently enough

light can be emitted

Compared to ultraviolet waves, the wavelength of infrared waves is

longer

Compared to ultraviolet waves, the frequency of infrared waves is

lower

Light travels slightly slower in the

lower atmosphere

The Moon would be at its fullest just before the time of a

lunar eclipse

When an astronaut on the Moon experiences a solar eclipse, observers on Earth see

lunar eclipse

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

magenta

A main difference between a radio wave and a sound wave is

medium or no medium

A lunar eclipse occurs when the

moon passes into earths shadow

What is the wavelength of an electromagnetic wave that has a frequency of 3 kilohertz?

more than 1 km

What is the wavelength of a 1-hertz electromagnetic wave?

more than 1 m

the cones in the retina of the eye are

most densely packed at the center of vision.

can you see or hear radio waves?

neither

The sky is blue because air molecules in the sky act as tiny

optical tuning forks that scatter blue lights

Electromagnetic waves consist of

oscillating electric and magnetic fields.

A partial solar eclipse occurs for people in the Sun's

penumbra

Which of these has the longest wavelength? (x, ultra, light, radio, infrared)

radio

Kids in elementary school get this right: Which color of light gets through red glass?

red

Magenta light is a mixture of

red and blue light

The LEDs that make up the color on some TV screens are

red, blue, green

If the atmosphere were about 40 times thicker, the Sun at noon would appear

red-orange

The color of an opaque object is the same as the light that is

reflected

You can get a sunburn while under the "shade" of a beach umbrella due to

reflected sunlight from the sand

When ultraviolet light is incident upon glass, atoms in the glass

resonate

In the periphery of our vision, we are

sensitive to movement, but cannot see color

In free space, electromagnetic waves travel at a

single speed

Short wavelengths of visible light interact more frequently with the atoms in glass than do longer wavelengths. Does this interaction time tend to speed up or to slow down the average speed of short-wavelength light in glass?

slow down

A new Moon appears in the sky just before the time of a

solar eclipse

Which of these is fundamentally from the other? (light rays, sound, gamma, x, radio)

sound waves

A pair of sunglasses and a pair of clear reading glasses are left in the sunlight. The hotter glasses will be the

sunglasses

the size of your pupils depends on

the brightness in the room and your mood.

A solar eclipse occurs when the

the moons shadow is cast on earth.

Compared to the velocity of radio waves in vacuum, the velocity of visible light waves in a vacuum is

the same

Consider light energy that is momentarily absorbed in glass and then re-emitted. Compared to the absorbed light, the frequency of the re-emitted light is

the same

The speed of light in the void between molecules in glass is

the same as its speed in a vacuum

Metals are shiny because

their electrons vibrate to the oscillations of any incident light.

Red-hot and blue-hot stars that are dim in the night sky appear white to the eye because

they are too dim to fire the cones

Sunburns are produced by

ultraviolet light

The natural frequency of the atoms in glass is in the

ultraviolet part of the spectrum

A total solar eclipse occurs for people in the Sun's

umbra

The dimmest part of sunlight is

violet

Glass is transparent to

visible light

Which of these has the shortest wavelength? (x, ultra, light, radio, infrared)

x- rays

If Earth's atmosphere were appreciably thicker, snow would appear

yellow

If only one color is absorbed in the pigment of a particular blue paint, that color would be

yellow

The complementary color of blue is

yellow

A blueberry will look black when illuminated with

yellow light

A fast-moving ball is more easily seen if it is

yellow-green