SEEING THINGS & REFRACTION Flashcards
What is light?
A way of transferring energy
What is luminous?
Object that gives out light
What is non-luminous?
Object that does not give out light
Why do you see things?
It reflects light and is luminous
How does light travel?
In a straight line
What is transparent?
See through
What is translucent?
Lets light through but is not see through
What is opaque?
Light can’t pass through
What are the three things light can do?
Can be transmitted (Light goes through a medium)
Can be reflected (Light bounces off surface)
Can be absorbed (Light does not pass through, energy converts to heat)
How are shadows created?
Light tries to go through an opaque surface but is reflected and absorbed.
Does light need a medium?
No
What happens when light is absorbed?
When absorbed stays in the object in the form of thermal energy
What is refraction?
The ‘bending’ of light when light travels from one medium to another
Why does refraction happen?
Because the speed of light is different in different mediums
How does light travel in a vacuum?
Constant speed
How does light travel in a denser medium?
Slower than the speed in a vacuum
Why does light bend?
Because light is slower in a denser medium, when it speeds up, it bends back.
Where does the change of direction happen?
At the boundary, or the interface between two medias
What is real depth?
The real depth of something due to refraction
What is apparent depth?
What the brain thinks the depth of something is (Shallower)
Formula for refractive index
Refractive index = speed in vacuum / speed in medium
Denser = Light bends _______ the normal
towards
Less dense = Light bends ________ the normal
away from
