Physics Images in Lenses (lesson 8) Flashcards
Light propagates
linearly
Refraction is when light bends after entering
a second medium
A lens is an optical device with
axial symmetry
A lens transmits light but can also
refract the path of light
Lenses will produce
real and virtual images
There are two basic lens shapes
Converging Lens
Diverging Lens
when light enters a lense
once when light enters
once when light exits
it refracts twice
from air into the surface
from the surface into the air
The angle of incidence is larger than the criticle angle to allow no refraction
but only reflection
light traveling with with 0 degrees will pass right through the surface of water with
no refraction
As the angle of incidence from underwater increases the refracted ray moves
AWAY from the normal
The angle of incidence will be that the refracted ray would be flat on the boundary between two media
Critical angle
All the light will reflect back to the water
total internal reflection.
The incident ray travels parallel to the principal axis, the refracted ray would
refract in a path that passes through the principal focus
For total internal reflection
light needs to go from
slow to fast medium
The refraction ray bends AWAY from the normal when the light travels from
a slower medium into a faster medium
The amount a transparent material slows down
the speed of light
N=c/v
n= index of refraction
c=speed of light in air
v=speed of light in refracted medium
FST
fast, slow, towards
Converging Lens
Focuses light rays at the principal focus
Thicker at the center than at the edges
Magnifies or makes objects look larger
(except beyond 2F1)
Can form real images
Diverging Lens
Spreads out light rays
Thinner at the center than at the edges
Makes objects look smaller
Cannot form real images
Thin Lens Equation
1/f=1/do+1di
diverging lense.
L=closer
O=Upright
S= Smaller
T=Virtual
Convex mirrors
L=closer
O=upright
S=smaller
T=virtual
can u say virtual?
