physics quiz Flashcards
how does a rearview mirror work using both reflection and refraction
It uses reflection for the image and refraction to control brightness.
hyperopia
far-sightedness
eyes cannot focus on nearby objects
eye to short
corrected by converging lens
how does total internal reflection occur
light travels from a medium with slower speed to a medium with faster speed
Distinguish between the types of light emissions
Sun: Nuclear fusion
Incandescence: Heat
Electric Discharge: Sparks
Phosphorescence: Glow
Fluorescence: Quick glow
LEDs: Electrons
Chemiluminescence: Chemicals
Bioluminescence: Life
Triboluminescence: Friction
Concave mirror points
Beyond C: smaller, inverted, between C+F, Real
At C: Same Size, inverted, at c, real
between c+f: larher, inerted, beyond c, real
At f: No image
Before F: larger upright, behind the mirror, Virtual
optical density (controls determines the direction of the refracted ray)
refers to a mediums transparency and its ability to decrease of increase the speed at which a wave travels
what s partial reflection/refraction
some light that is travelling from one medium into another is reflected and some is refracted at the boundary between the mediums
myopia
near-sightedness
eyes cannot focus on distant objects
eye to long
corrected by diverging lens
Describe how light is emitted
Absorb, Excited, Release
what happens when a light ray moves from a less optically dense medium to a more optically dense medium?
- speed of light decreases
- the light ray bend toward the normal
- there is a smaller angle of refraction
applications of total internal reflection
binoculars
cables
optical fibres
convex mirror points
In front of mirror: smaller, upright, behind the mirror, virtual
what determines how much light is reflected and how much is refracted
- angle of incidence
- relative indices of refraction
what is a critical angle
the angle of incidence produces an angle of refraction at 90*
equation to determine angle of refraction
n= c over v
n= index of refraction
c= speed of light in a vacuum
v= speed of light in a medium
total internal reflection
incident light is not refracted but its entirely reflected back from the boundary
what does the index of refraction depend on gases
- temperature
-pressure
What is Fermat’s principle
Predicts the path that light will take after reflecting from a surface or passing through more than one medium.
Light always follows the path that will take the least amount of time.
what happens to the speed of light when it passes from one medium to another and what effect does this have on the ray light
the speed changes and the wave bends (changes its path)
what does the index of refraction depend on solids and liquids
- temperature
-pressure (but to a lesser extent
identify real life applications of convex mirrors
- mirrors in all vehicles
- sunglasses
- magnification glasses
parts of the human eye
- cornea
- retina
- macula
- pupil
- sclera
- lens
- ciliary muscles
- optical nerve
what is refraction
refraction is the bending the waves due to a change in speed as they travel between media
when does total internal reflection occur
occurs when the angle of incidence produces an angle of refraction at 90*
what happens when a light ray moves from a more optically dense medium to a less optically dense medium?
- speed of light increases
- the light ray bends away
- there is a larger smaller angle of refraction
difference between a real and a virtual image
Real: reflection in front of the mirror
Virtual: Reflection behind the mirror
