Chapter 11/13 Color and Light
Electromagnetic waves (can/cannot) travel through a vacuum
Can
If the Sun were to disappear rn, we wouldn't know about it for 8 min because it takes 8 min for
Light to travel from Sun to Earth
Relative to the uv waves, the wavelength of infrared waves is
Longer
Red sunsets are the result of the
Longer path of air through which sunlight travels
If a light signal and a radio signal were emitted simultaneously from Alpha Centauri, the first to reach the Earth would be the
Neither. Both would reach Earth at the same time.
When light reflects from a surface, is there a change in its frequency, wavelength, or speed?
No
A laser beam is able to cut through steel because the energy in the beam can be _____ in a small area
concentrated
A ________ mirror produces a virtual image that seems smaller than the object and farther away than it really is
convex
What is the approximate speed of light in a vacuum?
186, 000 miles/ second
A whitish sky is evidence that the atmosphere contains
A mixture of particle sizes
One light source that does not depend on heat is
A neon sign
A band of colors called the visible spectrum can be produced by rays of light passing through
A prism
A variety of sunset colors is evidence for a variety of ______ particles
Atmospheric
The sky appears blue because
Atmospheric particles reflect and scatter blue wavelengths of light
If a red light shines on a green object, the object appears
Black
If you mix the primary colors of PAINT, the result will be
Black
Red, green, and _____ are the primary colors of light
Blue
Optical illusions are actually caused by errors in the
Brain
One important difference between light waves and sound waves is that light waves
Can move through empty space
A pair of colored lights that can be combined to produce white lights are called _______
Complementary
All forms of energy that move through space at a speed of 300,000 km/sec (186, 000 miles/sec) make up the
Electromagnetic spectrum
True or False: Most of the electromagenetic spectrum consists of visible light
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 _____of 1000 Hz
Frequency
Number of complete waves passing a point in a second
Frequency
High frequency waves useful in fighting cancer
Gamma rays
High-frequency______ can kill cancer cells
Gamma rays
The electromagnetic waves with the shortest wavelengths are
Gamma rays
For radio reception, diffraction is
Helpful
Laser light can make _____, which are pictures that can be seen from all directions
Holograms
A laser beam would be least useful for
Illuminating A room
The light source warmest to the touch is a
Incandescent bulb
_________ rays are given off by hot objects
Infrared
Colors seen when gasoline forms a thin film on water are a demonstration of
Interference
A beam of light made up almost completely of a single frequency is produced by a
Laser
Relative to its avg speed in air, the avg speed of a beam of light in glass is
Less
Objects that produce visible light are known as
Luminous bodies
Look at a full-color picture in a magazine with a magnifying glass and you'll see that the inks used are
Magenta, cyan, yellow and black
The whiteness of clouds is evidence in the clouds for a variety of
Particle sizes
Small particles of light energy
Photons
The law of reflection holds for
Plane mirrors and curved mirrors
The main difference between a radio wave and a light wave is its speed, wavelength or frequency?
Two of these
Useful in killing germs
UV light
A sunburn is caused by the damaging effects of
UV waves
When light passes through a prism, the wavelengths refracted most are
Violet
The band of colors produced when white light is dicided into its seperate colors is calld the
Visible Spectrum
The colors of the rainbow are made up of waves of
Visible light
An iron bar has been heated to the point where it is giving off a yellow glow. Further heating will eventually cause the iron to produce light that is
White
If red, green, and blue light are combined, the result is
White light
Which of these electromagnetic waves has the shortest wavelength: radio, infrared, x-rays, uv or light waves
X-rays
Wilhelm Roentgen accidentally discovered
X-rays
________Pass through skin and tissues, but not bones
X-rays
The colored inks used to make printed color pictures are
Yellow, cyan, magenta, and black
The primary colors of paint are
Yellow, magenta, and cyan
If the angle of incidence of rays striking a plane mirror is 80 degrees, the angle of reflection is
80 degrees
The color of paints depends on which frequencies of light are ______ and which are absorbed
Reflected
As light rays move from one medium to another, they are
Refracted
The complementary color of blue is
Yellow
Colors of light that can be mixed to produce any other color are called
Primary colors
A specially shaped piece of glass called a ______ can divide white light into its separate colors
Prism
Complementary colors are two colors that
Produce white light when added together
Used to identify objects through darkness or fog
Radar waves
The electromagnetic waves with the lowest frequency are
Radio waves
Because it has the lowest frequency, _____ light is refracted the least
Red
The color found at the top of a rainbow is
Red
The wavelength of light refracted the least by a prism is
Red
List the 7 colors of the rainbow in order from lowest to highest frequency
Red Orange Yellow Green Blue Indigo Violet
Magenta light is really a mixture of
Red and blue light
A color TV picture is made by mixing lines of
Red, Blue and Green light
The colored dots that make up the color on a TV screen are
Red, blue, green
Light is _____ when it strikes a mirror
Reflected
As the frequency of an electromagnetic waves becomes higher, the wavelength becomes
Shorter
The electromagnetic spectrum does not include
Sound waves
A pair of sunglasses and a pair of clear reading glasses are left in the sunlight. The hotter glasses would be the
Sun glasses
Consider light energy that is momentarily absorbed in glass and then reemitted. Relative to the absorbed light, the frequency of the reemitted light is
The same
Relative to radio waves, the velocity of visible light waves in a vacuum is
The same