light Flashcards
what is a ray?
single line of light that tells us the different direction that the light is travelling in
what is a beam?
a collection of rays
how many types of beams are there?
3
what are the types of beams called?
-converging
-parallel
-diverging
what is self lumious?
e.g- sun, fire, lightbulb
these objects are able to make their own light
what is non-luminous?
e.g- books, moon, rocks
these objects do not make their own light and we are only able to see them when light reflected off their surface enters our eyes.
why can we not see objects clearly in a dark room?
there is no light to reflect
why should you do your homework at a well-lit desk?
so you can see your work clearly
why do some objects appear bright and shiny?
objects which are bright and shiny have smooth surfaces
in what shape does light travel?
straight lines
what is the speed of light?
3 million
how do shadows work?
when an opaque object is placed in the path of a beam of light, the rays are not able to pass through it. they are stopped or absorbed instead so we get a region behind the opaque object that no light reaches.
