Light on the Move
What is a narrow beam of light called?
Ray
What kind of reflection happens on smooth surfaces like mirrors?
a) specular
b) diffuse
a) specular
What is a substance that allows waves to travel through it called?
Medium
What are the three primary colours of light?
Red, green, blue
What is the name for the group of all the colours we can see?
visible spectrum
What type of material allows all light to pass through?
Transparent
What is the name of the 90° line used in ray diagrams?
Normal line
between which lines do we measure the angle of incidence from?
incident ray and normal
What part of the inside of the eye focuses light onto the retina?
Lens
What is the name of the spreading out of colours from white light?
Dispersion
What type of material allows only some light to pass through?
Translucent
What kind of reflection happens over a rough surface?
diffuse reflection
What change causes light to bend when entering another medium?
Change in speed
Which cells in the retina detect colour?
cone cells
What colour would a white shirt appear under blue light?
blue
What type of wave is light?
transverse
What is the Law of Reflection?
angle of incidence = angle of reflection
Which type of lens brings light rays together?
Convex (converging) lens
What colour is produced when red, green, and blue light are combined at maximum intensity?
White
What does a low frequency wavelength mean?
fewer vibrations/waves per second
Why do we see lightning before we hear thunder?
Light travels faster than sound
Name ONE feature of an image in a plane mirror.
objects are: same size / same distance from the mirror / left-right inverted
How is the emergent ray related to the incident ray after passing through a rectangular glass block?
Parallel
Why do television screens only have three colours: RGB?
RGB are the only colours the cone cells in our eyes can detect. All other colours we see are mixtures of these three colours.
how do rainbows form?
Rainbows form when white light from the sun is refracted by water droplets in the air into the individual colours of the visible spectrum