Definitions and Laws
The tiniest possible particle of light energy, impossible to see with your eyes:
Photon
Transparent (allows light to pass through).
True or False: Without light energy, you wouldn't be able to see anything at all.
True (page 335)
Suppose a photon is traveling through air. If the photon suddenly hits a lake, what will happen to its speed?
Since light travels more slowly in liquids than it does in gases, the photon will slow down when it hits the lake. (OYO 10.2)
Both mechanical and electromagnetic waves travel through _______.
Matter.
A transverse wave composed of oscillating electric an magnetic fields that are perpendicular to each other and to the direction the wave travels:
Electromagnetic Wave.
Transparent/ Translucent/ Opaque: Book
Opaque (absorbs or reflects light)
True or False: Electromagnetic and mechanical waves require a medium through which to travel.
False. Electromagnetic waves do not require a medium through which to travel, but they can travel through matter like mechanical waves.
If radio signals are really made up of electromagnetic waves, why doesn't a radio station's antenna glow when it transmits its signals?
A radio station's antenna does not glow because the light it emits is not visible. Radio waves have wavelengths longer than visible light. (OYO 10.5)
Einstein's theory explains that light ___ behave as both a particle and a wave.
Can. (wave-particle duality theory)
Consists of radio waves, microwaves, infrared waves, visible light, ultraviolet waves, x-rays, and gamma rays:
Electromagnetic Spectrum
Transparent/ Translucent/ Opaque: Fishbowl
Transparent
True or False: It is called absorption when light waves get redirected because they pass through molecules or particles:
False. It is called scattering. (OYO 10.10)
Consider a woman looking at herself in a mirror. How does she see her foot?
Light reflects off of her foot, hits the mirror, reflects off of the mirror, and enters her eyes. (Page 354-355)
The angle of incidence is the angle a light ray makes with a line _________ to an object.
Perpendicular.
Acronym, or man's name, used to memorize the relative size of color wavelengths:
ROY G. BIV, with red light having the longest wavelength.
Transparent/ Translucent/ Opaque: Wax Paper
Translucent (scatters light)
True or False: Light waves pass through Opaque materials.
False. Opaque materials absorb or reflect all light.
Light waves from the sun reflect off snow in mainly a horizontal plane. Would horizontally polarized or vertically polarized sunglasses block the sun's glare?
Vertically polarized sunglasses would block the horizontal wavelengths of light that reflect off snow. These glasses only allow vertical waves to enter them. (OYO 10.9)
_________ light is light waves that vibrate in only one direction - either vertically or horizontally.
Polarized. Unpolarized light is light waves from the sun that vibrate in all directions.
The angle of reflection equals the angle of incidence:
Law of Reflection
Transparent/ Translucent/ Opaque: Vegetable Oil
Translucent (scatters light)
True or False: UV-C waves are the most damaging of the Earth's ultraviolet waves, and are blocked by the ozone layer.
True.
Why does a red shirt look red to your eyes?
When we observe an object's color, we are seeing the wavelengths of light is is reflecting. A red shirt, then, absorbs all the wavelengths of visible light except for red, which reflects back into your eyes. Thus, you see red. (OYO 10.12)
Light travels more _______ in solids than gases.
Slowly.