Laws of reflection and refraction Flashcards
Define and give example. Absorption.
In terms of light and lenses- when a ray of light enters a lens some of the light will not completely travel through the lenses.
Define and give example. Deviation(angle of)
The angle a ray of light is changed from its original path
Define and give example. Diffuse reflection.
A reflection from a rough surface- the reflection does not produce a clear image
Define and give example. Incidence(angle of)
The angle which a ray of light makes with the surface of a refracting medium
Define and give example. Reflection.
The return of light waves from a surface. The production of an image.
Define and give example. Refraction.
The bending of light when going from one medium into another.
Define and give example. Refraction(angle of).
The angle created when a ray of light passes from one medium into another.
Define and give example. Specular reflection.
The forming of a clear image when light strikes a surface.
Label diagram
A. Incident ray
B. Normal to the surface (for the first refraction)
C. Angle of incidence (for the first refraction)
D. Angle of deviation (for the first refraction)
E. Angle of refraction (for the first refraction)
F. Angle of incidence (for the second refraction)
G. Normal to the surface (for the second refraction)
H. Angle of refraction (for the second refraction)
I. Emergent ray
J. Where the ray would have been if the sheet of glass were not there
K. Displacement of the ray from the original path
Why is the red pencil red?
It reflects red rays back toward the eye and absorbs all other rays of visible light
Why is the blacktop black?
It does not reflect any rays back toward your eye; rather, it absorbs them all
If a light beam passes through a green sunglasses lens, why will the exiting light be green?
The green rays are refracted through the lens and all other color rays are absorbed by the pigments in the lens material
When a ray of light travel from air into water(which is denser than air) what happens to the ray of light if the ray is perpendicular to the surface?
It slows down but does not change direction. It is not deviated or displaced.
When a ray of light travel from air into water(which is denser than air) what happens to the ray of light if the ray is not perpendicular to the surface?
It slows down and changed direction toward the normal. It deviates from its original path.
When a ray of light travels from water into air (which is rarer than water) what happens to the ray of light if the ray is perpendicular to the surface?
It speeds up but does not change direction. It is not deviated or displaced.
When a ray of light travels from water into air (which is rarer than water) what happens to the ray of light if the ray is not perpendicular to the surface?
It speeds up and changes direction away from the normal. It deviates from its original path.
What does critical angle mean?
A light ray leaving a denser material for a rarer material that is at an angle to the normal that results in it traveling parallel to the surface of the material. If the angle of incidence is greater than the critical angle the ray will reflect inside the material and will not exit into the rarer material.
If a light ray travels from air to water with an angle of incidence of 15 degrees and an angle of refraction of 11 degrees, how much did it deviate?
i=15
r=11
d=?
i=r+d
15=11+d
d=15-11
d=4
If the light ray leaves the water traveling into air with an angle of incidence of 20 degrees and it is deviated by -7 degrees, what was the angle of refraction?
i=20
r=?
d=-7
i=r+d
20=r+(-7)
r-7=20
r=20+7
r=27
The bending or redirection of a light wave when it passes a barrier without changing the medium in which it is traveling is called:
Diffraction
When a light ray travel from one transparent medium to another, it changes direction. This bending of light, which results from the differences in density of different transparent materials, is called:
Refraction
When a ray of light travels from one material to another, if its direction of travel is perpendicular or normal to the interface or junction between the materials, it will—
Change speed but not direction
When a ray of light travels from a less dense (faster) material to a denser ( slower) material at an angle to the normal, it will—
bend toward the normal
When a ray of light travels from a denser (slower) material to a less dense (faster) material at an angle to the normal, it will—
bend away from the normal
