Light Flashcards
What is light?
Light is a transfer of energy from one store of energy to another
Like when you move food from the cupboard to your mouth!
So true bruv!!
What form is the energy of light transmitted in?
The form of waves
Does light need a medium to travel through?
Eg. Water, air, brick
Nope! And the waves can still travel very fast over very long distances!
What direction does light travel?
IN A STRAIGHT LINE
not a wonky one
not a zigzag one
A STRAIGHT ONE
When does light stop?
Light travels through a medium until it hits another object
What are light rays?
Light rays are an imaginary line that shows the direction in which light is travelling
What is darkness?
An absence of light
no light at tall
None
Why are you still reading this
What does luminous mean?
Something that emits light
Like a lightbulb
What are the rules of drawing Ray diagrams?
- Use a ruler
- Use a pencil
- Use an arrow to show direction
Why can you not see far away things really really well?
Because light rays spread out so less light reaches your eye
Definition of transmitted?
Light hits and passes through
Definition of absorbed?
Light hits and stops
Definition of reflected/scattered?
Light hits and bounces off
How do you see an object?
You see a bottle when the light bounces off the bottle and into your eye
Definition of transparent?
Allow light through without scattering
Definition of opaque?
Doesn’t allow any light through
Definition of translucent?
Scatters light as it passed through
Definition of reflective?
A material that light bounces off
What is the normal?
A line at 90 degrees to a surface, drawn at the point where light hits the surface
Angel of incidence is…….
20 degrees from the normal, the angle between the normal and where the light is coming from
Angle of reflection is…….
The angle between the normal and the reflected ray
What colours is yellow made of
FOOLED YA BRUV!!
Yellow is not made up of any other colours. That doesn’t seem right to be honest but that is what the science book bible says…..
ENLIGHTENMENT!
The angle of reflection is …………….. to the angle of incidence
equal!!
What is depth perception?
When you see something in water where it isn’t because your brain thinks light travels in a straight line. Your brain is right, but light still changes direction when it enters something else.
Science beat ya brain bruv!!
Refraction is…….
When the angle of incidence is smaller than the critical angle.
What colours can the sensors in our eyes detect?
Red Green Blue
Red + Blue =
Magenta
Blue + Green =
Cyan
What happens if you shine yellow light through a prism?
The yellow light would stay the same and just refract
Red + Green =
Yellow
Mixing two types of light will always result in a
Brighter light!
What is the order of the rainbow?
Red Orange Yellow Green Blue Indigo Violet
Richard of York gave battle in vain
Red + Green + Blue =
WHITE
White light is made of
all the colours in the spectrum :)
What are the parts of your eye?
The cornea, the lens, the iris and the retina.
What is a cornea?
A transparent window with a convex shape. this is how your eyes focus.
What is a lens?
It changes shape behind the cornea to focus light from objects at varying distances
What is an iris?
The coloured part of your eye that controls how much light enters it.
What is a retina?
It is where images are formed (upside down). The cells in the retina are photo sensitive.
Which 2 angles are the same
The angle of incidence and the angle of reflection. They are both 20 degrees
