Chapter 8.2 Flashcards
What is the definition of rectilinear propagation
- when light travels through a homogenous medium
- >it travels in a straight line
What is a characteristic of plane mirrors
- they have flat reflective surfaces
- > so there is no convergence or divergence of reflected light rays
- > because the light does not converge, plane images always create virtual images
-the image in a plane mirror is the same distance behind the mirror as the object is in front of it
What is the center of curvature and the radius of the curvature in spherical mirrors
Center of curvature
->point on the optical axis located at a distance equal to the radius of the curvature from the vertex of the mirror
-in other words, the center of curvature is the center of the spherically-shaped mirror
Are concave mirrors converging mirrors or diverging mirrors
- concave mirrors are converging mirrors
- convex mirrors are diverging mirrors
Where is the focal length
- the distance between the focal point and the mirror
- >note that all spherical mirrors, f=r/2
What does it mean if an image is greater than zero(i>0)
- it is a real image
- >less than zero is a virtual image
Do plane mirrors have infinitely large focal distances?
- yes, for a plane mirror
- > r=f=infinity
- therefore, the equation becomes 1/i+1/o=0
- > i=-0
- > therefore, this can be interpreted as saying the virtual image is at a distance behind the mirror equal to the distance of the object in front of the mirror
What does a single diverging mirror form(convex mirror) in terms of realness, whether it is upright and whether it is magnified or reduced
-it forms a virtual, upright and reduced sized image
How is r(radius of the mirror) affected by a converging mirror and a diverging mirror? Describe focal length in this perspective too
R
- > positive for a converging mirror
- > negative for a diverging mirror
F
- > positive for a converging mirror
- > negative for a diverging mirror
What is the definition of refraction
- it is the bending of light as it passes from one medium to another
- > change of speed also comes along with this change from one medium to another
How does index of refraction relate to a vacuum and other materials
- it is a 1 for a vacuum
- >and greater than one for all other obkects
What happens to the angle when light enters a medium with a higher index of refraction
- it bends towards the normal
- > sin 1 theta>sin 2 theta
-vice versa for light entering a medium with a lower index of refraction
What does it mean to use the term critical angle
- it is light when refracted
- > has an angle of about 90 degrees
- > results in total internal reflection
- > a phenomenon where light incident on a boundary is reflected back into the original material
What are the differences between mirrors and lenses
- mirrors reflect light while lenses refract
- with lenses there are two surfaces that affect the light path
- > light is refracted twice as it passes from air to lens and from lens back to air
Where is the real side and the virtual side on the lens
Real side
->on the opposite side of the lens from the original light source
Virtual side
->on the same side of the lens as the original light source
