Where is the image that appears in a plane mirror?
Behind the mirror. It will also be upright
T/F. Red and violet light travel at different speeds
True. This is why when we say the index of refraction for glass is 1.5, it also means that the index varies for each photon. 1.47 for red, 1.54 for violet
Violet light has the greatest angle of refraction
Equation for critical angle
sin Ocrit = n2/n1.
n1 is index of medium that light is traveling through (incidence)
Senlls law
n1 sin O1 = n2 sin O2
Curved mirrors are also called?
Spherical
Distance b/w the center of curvature and the mirror is called the radius of curvature, r. So where is the focal lenght?
Halfway between the center of curvature. f = 1/2 r
Where is the image formed for concave and convex mirrors?
CONCAVE Infront of the mirror and it will be inverted
CONVEX Behind the mirror and upright
Lens and mirror equation
(1/o) + (1/i) = (1/f)
o = object's distance from mirror (always positive)
i = distance of image
f = focal length
magnification equation
m - i/o
if m is positive, the image is upright
if m is negative, the image is inverted
T/F. Real images are upright, and virtual images are upright
TRUE
Mirror shortcut.
f
Concave +
Convex -
i
i + = real image
i - = virtual image
m
m + = upright
m - = inverted
Usually i+ goes with m-; and i- goes with m+
Concave mirrors can create real and virtual images while convex mirros can only make virtual images.
Image of plane mirror
Virtual and upright.
(real always always goes with inverted, and virtual always goes with upright. since the mirror makes an upright image, it is virtual)
If an object is placed very far from a concave mirror, where will be the image form?
At the focal point
o = infinity so 1/o = 0, therfore 1/i = 1/f; i = f
f is always 1/r and r is always 2f!
Often the MCAT will give you the radius, so simply divide by 2.
How do lenses form an image?
Through refraction. Lenses are clear pieces of glass.
Converging lenses
Thicker around the middle.
Refract light rays that are parallel toward the focal point on the other side of the lense
Diverging lens
Thinner in the middle
refract ligth that are parallel away from the axis of the focal point = infront of lens
analagous to concave lens
Lens shortcut
Essentially same laws and rules except that converging lenses (convex) have a postive value for f while diverging lenses (converging) have a negative value for f.
i
i + = real image
i - = virtual image
m
m + = upright
m - = inverted
Usually i+ goes with m-; and i- goes with m+
Where are virtual images formed?
Same side of the lens/mirror as the object; real and inverted on the other side
Lens with a shorter focal lenght refracts more or less light?
More, which also means that is has greater power
Lens power
P = 1/f; D in diopters; f in meters
Define myopia and hyperopia
myopia = nearsightedness (Cannot see far). Fix with digerging lens.
hyperopia = farsigtedness (Cannot see near). Fix with converging lens.
