wave model + ray model flashcards

what type of wave is light according to the wave model

electromagnetic wave, and two dimensional

what are the two dimensions of the light wave

electrical and magnetic

what does the type of wave depend on

wavelength (or frequency)

what do all light waves travel at

speed of light c = 3×10^8

Radio wave

wavelengths > 1m. AM = kHz frequencies, FM = MHz frequencies

Micro waves

Wavelengths > 1mm, Matches resonant frequency of water

Infrared

1mm > Wavelengths > 750nm. Heat. Some animals can see infrared

VIsible Light

Wavelengths between 400-750nm, The rainbow

Rainbow order

ROYGBV. Red = longest wavelength, Violet = shortest wavelength

Ultraviolet (UV)

High enough energy to brown skin, correlation with skin cancer

X-Ray

High enough energy to pass through soft tissue, high correlation with cancer

Gamma

Caused by nuclear reactions, enough energy to alter DNA

What does wavelength determine

visibility and color

Retina

layer on the back of the eyeball containing photoreceptors

what do rods and cones determine

rods = picture, and cones = color

what happens when light strikes a photoreceptor

it sends a signal to the brain

what is colorblindness caused by

improper functioning of the cones, either with a insufficient chemicals used by cones or insufficient number of cones

most common color blindness

red-green

three cones humans have

RGB

who first discovered white light is made up of all colors of the rainbow

Primary colors

red, green, blue

primary colors of pigment

magenta, cyan, yellow

how do we see an object

light traveling from the object to our eye

how does an object reflect light into our eyes

the object emits light or reflect it, and these rays travel in all directions until it hits our eyes

the law of reflection

the angle between the incident ray and normal equals the angle between the reflected ray and the normal

diffuse reflection

the surface scatters the reflected light in all directions, where each ray obeys the law of reflection

Specular reflection

the reflected light maintains the same pattern as the incident light

what is specular reflection (not the definition)

a mirror image

how do we describe a mirror image

using a flat (plano) mirror to produce the image. this makes a virtual image where image distance equals object distance and image height equals object height

Convex

middle of mirror sticks out, diverging (reflected rays spread out)

Concave

middle is caved in, converging (reflected rays come together)

what do curved mirrors do to images

they now have different sizes, orientations, and location