P14 - Light Flashcards
What is reflection
When a wave hits a boundary/surface and instead of travelling to the new medium, it bounces back
What is the normal line
The line perpendicular to the surface/ boundary
Angle of incidence = _______?
Law of Reflection
Angle of incidence = angle of reflection
The incidence and reflected rays also have the same frequency, speed and wavelength
What is specular reflection
Reflection from a smooth surface where all of the reflected light rays go in one direction
What is diffuse reflection
Reflection from a rough surface where the reflected light rays are scattered in different directions
What is a virtual image
The image from which light rays appear to be coming from
Describe the image formed by a plane mirror
Virtual, upright and laterally inverted
Defenition of Refraction
The change in direction of a light ray as it passes the boundary between two different transparent substances
How do colour filters work?
They absorb certain colours and transmit others e.g. white light on a red filter only allows red light through
Primary colous of light
Red, green, blue
Secondary colours of light
Cyan, Yellow, Magenta
What colour would a red object look like through a blue filter
Black as all colours would be absorbed
Why does an object have a certain colour e.g. a red apple
The apple absorbs all other colours and only reflects the red
Defenition of transparent object
An object that transmits all the light that enters it
Defenition of a translucent object
An object that tramsits all the light, but it is refracted in the process
