Light Flashcards
(33 cards)
Primary colours
Colors that cannot be made by mixing other colours
What happens when you add
Red+green
Red+blue
Blue+green
Yellow
Magenta
Cyan
What are the different colours you see on your phone computer and television produced from
All produced from the mixing of the three primary colours
Elaborate more
. Most screens can display 256 different colours. Changing the brightness of the primary colours makes all these different colours. For example, orange is made by adding red and green, but with the red brighter than the green.
What are filters
Used to remove something from a mixture
Colored filters
To remove colours from light
What happens when a transparent piece of colored glass or plastic is placed in front of white light?”
only light of that colour will be transmitted (get through). All the other colours will be absorbed.
What purpose do the colored filters serve in front of the white lamps used in traffic lights?
Red,yellow and green
What is white light from a lamp made out of
7 different colours:red orange yellow green blue indigo violet
Give and example of subtraction of light
White light had six colours subtracted to only reflect light
Do the yellow and green filters in traffic lights work the same way by absorbing multiple colors and transmitting only one color?
Bach on them absoros six colours and only transmits one colour.
Why does the red filter in traffic lights only let the color red pass through while absorbing the other six colors?
When these seven colours arrive at the red filter, only red is transmitted. The other six are absorbed.
Explain how sundials work
As the sun changes in the sky, the shadow cast by the style moves across the surface of the sundial. The surface is marked with numbers, allowing the shadow to indicate time of day.
What were sundials used for and when
Used as a time keeping device and used in the ancient times
Where does light come from
Light is emitted by luminous objects , like the sun and light bulbs
Some objects do not emit light but just reflects give example
The moon
It’s non luminous
How do shadows form (4)
A shadow forms when the light from a light source is absorbed by an opaque object
Shadow forms because light travels in a straight line, it cannot bend round corner.
The are where the shadow is is darker because less light reaching it.
A shadow forms when an opaque object blocks the light
What happens when the light passes through the object
It has been transmitted.
The material is transparent
What happens when the light is absorbed by the object
The object gets warmer
The material is opaque is doesn’t allow light to pass through
What happens when light bounces of the object
We say that ipthe light has been reflected
What is light
Light is a source of energy
Light is a wave
It can be reflected and refracted
Light travels in a straight line
Light is made up of 7 different colors
What is a ray
A single line of light is called a ray
The law of reflection
-the angle of incidence is equal to the angle of reflection
- the normal the incidence and the reflected ray all lie on the same plane
Normal
Is a straight dotted line drawn from the point of the incidence at 90°
