46 terms

Abeka Physics Chapter 20

This set is currently a work in progress. It will cover A Beka Book Physics Chapter 20: "The Refraction of Light" (pages 292-308).

Terms in this set (...)

optical density
term for a material's resistance to the transmission of light waves
wavelength, speed
When light enters a new medium, _____ and ___ change.
decrease
The wavelength of light entering an optically denser medium must _____.
increase
The wavelength of light entering a medium of lower optical density must ______.
refraction
term for the bending of light rays at the boundary between two media differing in optical density
transmitted
If two adjoining media have the same optical density, light is fully _____.
absorbed, reflected
If a new medium is nontransparent, light is partly ____ and partly _____.
transmitted, reflected
If both media are transparent, but have different optical densities, some light is ____ and some is ____.
refractive index
term for the index that relates the speed of light in a vacuum to the speed of light in a particular medium
refractometer
term an instrument that measures refractive index
angle of incidence
term for the angle between an incoming ray and the normal to the boundary
angle of refraction
term for the angle between a refracted ray and the normal to the boundary
n1 sin θ1 = n2 sin θ2
the first law of refraction
Snell's law
another term for the simple relationship expressed by the first law of refraction
principle of reversibility
principle that states that the path of a light ray subjected to reflection or refraction is traced in reverse by any ray coming along the path in the opposite reaction
mirage
A ____ of water is due to the refraction of sunlight as it passes through hot, expanding air at ground level.
critical angle
When the angle of incidence reaches the ____ ___, the angle of refraction becomes 90 degrees.
total internal reflection
term for reflection as a result of an angle of incidence greater than the critical angle
convex
term for a bulging surface with the same curvature as the surface of a sphere
concave
term for a caved-in surface witht he same curvature ast he surface of a sphere
planar
term to describe a flat surface
convergig lenses
term for lenses that redirect parallel rayst oward a point of convergence
double convex lenses
the most important converging lenses
diverging lenses
term for lenses that spread parallel rays apart
double concave lenses
the most important diverging lenses
positive
Convergenging lenses have a _____ (positive, negative) focal length.
negative
Diverging lenses have a ____ (positive, negative) focal length.
normal
term for the perpendicular to a plane at the point of tangency
principal axis
term for the axis which is perpendicular to the lens plane
principal focal point
term for the point of convergence on the opposite side of the lens, to which rays are directed
optical center
term for the center of the lens
focal length
term for the distance from the optical center to the principal focal point
secondary focal point
another term for the focal length
optical plane
term for a plane perpendicular to the principal axis at the optical center
parallel ray
term for a ray that travels parallel to the principal axis, and then refracts through the mirror to the principal focal point
central ray
term for a ray that pases through the optical center of a lens without deviation on the far side
focal ray
term for a ray that aproaches the lens through the focal point
real image
term for actual light rays intersecting after refraction
virtual image
term for light rays extending from a lens in order to intersect
1/f = (n-1) (1/r1 - 1/r2)
the lensmaker equation
1/f = 1/do + 1/di
the thin lens equation
myopia and hyperopia
two defects of vision that can be corrected by wearing eyeglasses or contact lenses
myopia
term for nearsightedness
hyperopia
term for farsightedness
P = 1/f
the equation for the power of a lens
diopter
the unit for the power of a lens