chapter 5 Flashcards
what can happen when light falls onto a surface
reflection
transmission
absorption
refraction
dispersion
what is a regular reflection
occurs on a smooth and shiny surface that the // beam reflects back as a // beam producing a clear and undistorted image
what is an irregular reflection
occurs on a surface that is not smooth or straight, causing the //beam to be reflected back in all directions producing a rough and dull image or none at all
what is a virtual line
an imaginary line eg normal
what are the characteristics of a plane mirror
upright
laterally inverted
virtual
same size as object
reflection same distance between object and mirror
what is the incident ray
the light ray which strikes the flat smooth shiny surface
what is the normal
a virtual line at 90 degrees
what is the reflected ray
a ray reflected back into the viewers eye
whats the relationship btwn incident and reflection ray
both are equal
what is refraction
the bending of light from one medium to another of different optical density
why does refraction occur
speed of light changes as it travels through different mediums
where does light bend towards when it travels from less dense to denser medium
normal
where does light bend towards when it travels from denser to less dense medium
away from normal nearer to incident ray
what is the relationship btwn emergent and incident ray
they are parallel
when the light ray is coming at 90 degrees does anything happen
no because 90 degrees is the normal so its an exception
explain why light bends when it enters a glass block
light travels from air, a less dense optical medium to glass, a denser optical medium, hence it changes its speeds and bends
what are some effects of refraction
- a straw appears bent in a glass of water
- objects in water appear closer to the surface
- pool appears less shallow than it actually is
why does a pencil appear bent in a glass of water
as light travels from water to air, light travels from an optically denser medium to a less optically dense medium. light then bends away from the normal. the observer sees the pencil at a virtual position, making it appear nearer to the surface than the actual position of the pencil
what is dispersion
occurs when white light enters a glass prism, the light splits into 7 different colours called a spectrum
why does dispersion occur
each colour making up the white light is refracted at different angles bc each colour travels at different speeds as it travels from air to prism
what colours make up white light
violet
indigo
blue
green
yellow
orange
red
which colour is refracted the most bc it has the longest wavelength
red
which colour is refracted the least bc it has the shortest wavelength
violet
whats the inner curve called
concave
