Types of Light Sources
emission of light from a living organism is called
Bioluminescence
light travels in ______
Light travels around ___________ km/s
straight lines
300 000 km/s
What is a concave mirror and what does it do to reflections?
Curves inward, images are larger and magnified but when far away they are inverted and smaller
What is refraction?
When a wave of light bends entering a different medium (substance)
What happens when light enters a more dense medium?
it will bend towards the normal line
when something gets hot enough to emit light
incandescence
light can be _______ (bounce) and __________ (bend)
reflected and refracted
What is a convex mirror and what does it do to reflections?
Explain the difference between an incident ray and a refracted ray
A refracted ray is a ray of light that has been transmitted into a different medium which cause the ray to bend in a different direction
What happens when light enters a less dense medium?
It will bend away from the normal line
Fluorescent
luminous: produces light: sun, fire
non-luminous: reflects light: moon, chair
What is the Law of Reflection?
the angle of reflection will always equal the angle of incidence for a ray of light that is reflecting off a surface
What is the 'normal line'?
The line that is perpendicular to the surface of the medium that the ray of light is travelling through
When light travels from a less dense medium to a more dense medium, what happens to its speed?
It slows down
emission of light by charged particles after they have been exposed to light energy
phosphorescence
Explain the difference between transparent, translucent, and opaque and what the light rays do
transparent: light rays go through
translucent: some light rays go through, some get reflected or absorbed
opaque: light rays get reflected or absorbed
What is the difference between a specular reflection and a diffuse reflection?
Specular comes from a smooth surface and shows a clear reflection while diffuse comes from a rough surface and scatters the reflection.
What is the angle of incidence and angle of refraction?
Angle of refraction: the change in direction after a ray bends
When light travels from a more dense medium to a less dense medium, what happens to its speed?
It speeds up
emission of light due to the energetic reactions between two chemicals in a chemical reaction
chemiluminescent
explain the difference between light being transmitted, reflected, and absorbed
transmitted: when light goes through an object
reflected: when light bounces off an object
absorbed: when light passes into and not through an object (energy is transformed)
What is the difference between a real image and a virtual image?
A real image happens when actual light rays meet at a point and you can project it onto a screen (example: camera).
A virtual image happens when light rays only appear to meet - they don't actually converge, but your brain thinks they do (example: mirror)
What is the purpose of the normal line in refraction diagrams?
To compare angles of incidence and refraction
What happens when light passes from air into water?
It bends towards the normal and slows down