ray diagrams flashcards

how do we find the image of a curved mirror

the image forms where the reflected rays meet, and only two are needed to find the image

principal axis

the normal line through the center of the mirror

focal point

the point on the principal axis where all rays parallel to the principal axis reflect to

Center of curvature

the point on the principal axis where all normal lines meet. It is a 2x farther away than the focal point

Ray 1 of curved mirror

begins parallel to the principal axis and reflects through the focal point

Ray 2 of curved mirror

begins going through the focal point and reflects prallel to the principal axis

Ray 3 of curved mirror

goes through the center of curvature and reflects through the center of curvature

how do we describe a mirror image

one end of the object is always be on the principal axis, so the image will have one end of it as well. All incident rays start at the other end of the object ,so the reflected rays will meet at the other end of the image

what are the different types of lenses

converging : concave mirror and convex lens. Diverging: convex mirror and concave lens

what does (f) and (f’) stand for

primary focal point (f) and secondary focal point (f’)

Ray 1 convex lens

starts parallel to the axis, refracts through f

Ray 2 convex lens

starts through f’, refracts parallel

ray 3 convex lens

through center of lens

what is different from convex to concave lens in ray rules

f and f’ switch sides

Ray 1 concave lens

starts parallel to the axis, refracts from f

Ray 2 concave lens

starts toward f’, refracts parallel

Ray 3 concave lens

through center of lens

lens (mirror) equation

1/do + 1/di = 1/f where do = object distance, di = image distance where distance is from lens

magnification equation

m = -di/do = hi/ho where h = size (or height), m = magnification (no units)

the cornea is a…

fixed converging lens

Iris

aperture that automatically responds to light levels

Lens

flexible converging lens responsible for fine-tuning (accomodation)

how does the eye produce an image

image forms on the retina while the cornea, iris, and lens aid in forming the image

Farsighted

one can see objects far away but not near

causes of farsightedness

cornea is too flat, eyeball is too flat, image forms behind the retina

fix for farsightedness

use a converging lens to help focus light sooner

nearsighted

one can see near objects but not objects far away

causes of nearsightedness

cornea too rounded, eyeball too long, image forms in front of retina

fix for nearsightedness

diverging lens to focus light later

astigmatism

the cornea doesn’t focus light equally in all directions

astigmatism fix

cylindrical lenses